Hello and welcome to Just Answer!
The good news is, I can definitely tell you how the unlock procedure is done, the bad news is, you probably won't be able to unlock it yourself, nor will I be able to over the internet.
Older radios had a code that you could enter, and GM realized that it was to easy
So instead, radios like yours, have the vehicles VIN programmed into it.
Every time you turn the key on, the radio compares its programmed VIN with the cars VIN. If they match, the radio works.
If not, they radio locks.
why should have to pay for nothing if you can;t help me
then all you have to do is ask for a refund and your deposit will be refunded.
how do i do that
I will do that for you and I will say no more...
thank you so much