ESA Claim - No Medical - into Support Group

Went to a tribunal last year, August to appeal against being disallowed ESA after being on IB for 15 years. Lost the Appeal - there were a few grounds for taking it further but I decided not to bother I was so disheartened. I made a further claim for ESA in October 2013 got a letter saying not entitled to any money etc etc but would receive NI contributions. The letter also stated that I would be expected to attend for a Medical Examination in order to continue receiving NI credits. So I waited and waited. Nothing. Got a letter from my GP surgery asking me to go and see them as they had a letter from DWP requesting further information about medical conditions. Tried to make an appt and the receptionist knew nothing about the letter and could not find anything relevant to it. I rang DWP explaining the situation - they weren't exactly helpful, and said ATOS were dealing with the matter and I would have to wait till they contacted me for a medical and according to the notes on the screen, this would be after 2nd January. I waited. Nothing. Last week I received the dreaded brown envelope. With shaking hands I opened it expecting to find a date for medical. No. I have been placed in the Support Group and will be paid accordingly, plus arrears but only from December 2013 and not October when I submitted the claim. I don't know how they work that out. When I filled in the claim form I enclosed a statement from my GP surgery which states that they are not in a position to give letters of support to patients for DWP purposes and they do not intend to use the Doctor's time to police the benefits service and that the DWP must approach the doctor formally, through the recognised and approved channels when a fee will be payable by DWP. When I first applied, I did get a letter of support from my GP which ATOS chose to ignore at the time of my medical examination. So it looks like people need to find a way of getting the DWP to approach your GP directly for medical information because I am sure that is what has swung the decision in my favour. My medical conditions have not changed since my first IB/ESA form was submitted.
If anyone has any information about when the award should be back dated to - I would be grateful for their input.
Cheers
Liz