I got email for turbo tax saying the reason my refund was not what they said it the rebate credit on 1040 line 30 had amount $3,600 can you explain this to me. Thank you.

Lots of people made mistakes with the recovery rebate credit.   You were asked if you received the first and second stimulus amounts ---- and if you answered incorrectly then the software put the stimulus on line 30 and it was added to your refund.   You cannot get it twice.   The IRS cross checks to see how much you really received and if you answered that you received less than you actually received they recalculate and reduce your refund.