PIP Mandatory reconsideration questions

Hi,

We sent off an PIP MR about 3-4 weeks ago and haven't had any kind of acknowledgment. When we did the initial call to get the forms, we said no to giving a phone number and to remove any old numbers and do everything by post, in fact, we did this twice as we got cut off the first time. Within a few seconds of completing the second call, we started getting texts, despite telling them that this number was no longer used, and then texts and calls all the way through the process, which obviously weren't answered.

So when we did the MR, we just assumed that it would be all the same kind of thing, where they acknowledge receipt of the letter and then ignore you for a while and then tell you, it's a no. But we haven't heard anything at all. We sent by special delivery, so we have proof of delivery, but still, it seems to be a bit odd, so I wanted to ask here.

Should you get an acknowledgement of the MR letter when they receive it? Even by post, it would have got here a while ago.

Also, what kind of timescale (ish) are we looking at for them to look at it, in the North West of England?

And is it worth ringing to see where we are, or do we just have to sit it out?

Thanks!