Deductions & credits

I don't believe that the irs is cross checking every return for the right stimulus amounts they gave out because like I said in my other post, I only received stimulus money for myself the first 2 rounds but put in the extra amounts for my son through guidance from turbo tax and they accepted my return and sent out my return in 2 weeks. Had they checked it they would have seem the mistake or maybe they left it that way so they wouldn't have to give me the extra 1,100 I'm entitled to. 

I still haven't amended my return yet. Not totally sure how to do it and if the irs is going to accept it since I gave them wrong amounts which I added money so that doesn't look good on my end. 

Any advice would be appreciated