HMRC have lost my tax credit claim...

[Sweetasstevia]

I know they received it though as I sent it Royal Mail 'signed for' and I can see a signature when I track it.
.. I found out today that they don't have it when I phoned to chase our claim. The agent I spoke to said someone will call me once they have had another look and if they can't find it they will send out a pre filled form to us. Will I have to wait another 5 + weeks until my first payment? Also will the payment when we do get it be back dated to 25th November (the date I sent off my original claim).
We are really struggling at the moment and this is the cherry on the top of a difficult time :(

Anyone?

did you take a copy?
phone your MP

Yes I have a copy.

Cool.
Make a copy of your copy and send it to them again, with a covering letter entitled FORMAL COMPLAINT and let rip at them

make sure you copy your MP in.

then phone them, keep hitting 0 or # until you get a human and inform them that you have raised a formal complaint, raised it with your MP and will expect interest on the backdated payments

it won't happen but it WILL speed things up.

Excellent - thank you very much for the advice