PIP - Mandatory Reconsideration Request

I was recently re-assessed for pip and having received my decision letter they decided to reduce my mobility component to standard.

I have sent my Mandatory Reconsideration request by letter to the DWP, including all my findings to the PA4 and all relevant evidence.

I sent it by royal mail ‘Signed For’ delivery method and it was delivered and signed for the very next day with still 4 days remaining on the month long deadline limit.

My enquiry is, will I received a letter from the DWP confirming they have received my MR request.

Since completing my pip reviews forms to now it’s already taken over 16 months so far.

Do you have any idea how long the MR stage is likely to take?

I would appreciate your guidance regarding this matter.

Thank you very much for all your help.