if you're seeking a shop that can bend it for you, they'll need a manufacturer's license because, effectively, it will be a receiver manufactured by them once they bend it.
It will then need their name engraved onto it with a serial number.
If this is what you want, you should just buy a pre-made receiver on the internet. Now be gone with you!
Here is a "poor man's" bending jig you can buid it for about $30. There are mant variations and methods for bending a flat. Please google "poor man's jig" or "bending an ak flat". Also search youtube. There is a lot of building stuff on there.
You should seriously look at Boris's build threads. He has a few picks of the jig he made and a similar one can easily be created by stock from home depot or Lowes and a drill. Crude is alright, its an AK!
Hell I bet with a little patience you could just clamp it in a vice and hammer it to shape.