Are you sure you were supposed to get a refund? Look at your Form 1040 and see if there is an amount on line 35a. Or did you have a tax due amount on line 37?
Did you have an amount on line 30 for the recovery rebate credit? if the IRS thinks they already sent your 1st and/or 2nd EIP payment then they may have recalculated your refund and you may owe now instead of getting a refund. Their letter should explain what has been changed.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**