Change of address requirements for ESA & SMI

Hello,
This is my forst post and was wondering if anyone could advise :
In receipt of ESA, DLA and SMI, was living in England, just moved to Scotland.
Put house up for sale in February 2013, notified ESA dept and asked if I would still qualify for SMI on next property purchased with a mortgage. Advised yes, so requested a letter to confirm this which I received in February 2013, detailing only requirement is the completion of a MI12 form and solicitors confirmation of sale price, purchase price and mortgage.
I asked what I would need to complete and for them to check to make sure the info was correct, advised only the MI12 form and to ring with new address later.
Requested MI12 form 3 times over a period of 1 month before one actually arrived.
The one that arrived came with a ESA1 (rr) form - an ESA re-application.
I rang ESA dept and got the name of the chap I was speaking to, discussed at length the situation and asked why I was sent the ESA1 (rr) form - he checked and advised it has been sent in error and shouldnt't have been sent and can absolutely confirm that all that is required is a MI12 form with supporting solicitors details regarding sale and purchase.
On obtaining a sale date (completion date) for my house in May 2013, I contacted the ESA dept to advise of address change, they advised they couldn't take details to change things until after I had moved and to ring back then (DLA were the same).
Notified ESA and DLA in writing and sent both recorded delivery a couple opf days before I completed and moved.
ESA sent a benefits letter 1 day after completion to my new address, highlighting the removal of the existing SMI.
No word at all from DLA dept.
Sent completed MI12 to bank with solicitors letters highlighting buying & selling details.
Bank completed their parts 7 &8 and the returned to DWP in SAE that came with the MI12 form.
ESA received it.
As no response I chased it by ringing the ESA dept. on 11th June, advised that although ESA dept. had received it, it was sent to the mortgage dept. on 3rd June, so advised to leave it for a week.
Rang back 18th June, advised that mortgage dept received it on the 5th June and to leave for another 3 days and if not heard ring back and they will chase it.
I left it until 1st July, rang again and advised it is still awaiting processing and they cannot chase it as they are only a call cventre and to just wait till they got around to it.
Rang back 2nd July as I wasnt happy with the answer of the 1st July, where I advised they could chase it and its been 4 weeks that they have had it, lady emailed dept asking them to ring and that they would ring before 4pm that day. No call was forthcoming.
3rd July I received a call from Aberdeen mortgage centre advising that they have the application but do not have the original motrtgage file which the previous office said they had sent but hasnt been received. They advised that they will email a request for it.
They also advised that a change of address is classed as a change of circumstances and therefore I need to fill in another form.
I explained I had been advised this was against what I had already been told, the lady was adamant an aditional form was required to highlight changes such as GP details.
I asked if this was like the ESA50 I had completed In Octomer last year, she said no its more like the initial form when I applied for ESA initially.

The questions are :
1. Who is correct, does another form other than the MI12 need completing.
2. If another form is required, what is this form called and what is the form number etc.
3. How long is this form pages wise and if it is a long form why is it long for changes such as GP etc, as the new address has already been actioned by ESA.
4. If this other form is a change of circumstances form does this have any negative effects ie. flagged up for re-assessment etc.
5. Is there any where that legislation can be checked to confirm the answer to 1. above.
6. Is there any underlying/sinister reason that the ESA mortgage dept in Aberdeen would require another form completing.

I only completed my re-assessment form ESA50 in October last year, and am in the ESA Support Group, DLA was awarded from October last year also and SMI has been ongoing for 4 years.

Thank you.

Hi Gordon,
Could the request be simplified to change of address for ESA.
As in what is required due to being advised by different people of different things, ie advised that no form is required for a change of address then being advised that an address change is classed as a change of circumstances and new GP details etc are required by ESA dept.
So, the questions would be :

1. Who is correct, does a form need completing.
2. If a form is required, what is this form called and what is the form number etc.
3. How long is this form pages wise and if it is a long form why is it long for changes such as GP etc, as the new address has already been actioned by ESA.
4. If this other form is a change of circumstances form does this have any negative effects ie. flagged up for ESA re-assessment etc.
5. Is there any where that legislation can be checked to confirm the answer to 1. above.
6. Is there any underlying/sinister reason that the DWP would require a form completing.