Recovery Rebate 2021

I was asked to enter in my recovery rebate info into line 30, I had to make a profile on the IRS website to access the proper information. I entered $2,800 into the line as asked. My return was something along the line of let’s say $10,000 however when I received the return it was short the $2,800 I entered into line 30. I didn’t understand, and if it was meant to be deducted in the first place why didn’t it do so at the time? I got mail from the IRS saying something was wrong with my info and to resolve the issue through the phone line or mail in what I felt I needed to prove my case. I had no idea what to send except screen shots of what I did? Because it was a failed effort each time to contact a live rep on the phone. What did I do wrong? Am I suppose to be deducted the $2,800? I tried to get it back to no avail.