Did not receive tax return even though it says I have.

Did you have the $1,800 on line 30?  Did you already get the first two Stimulus payments (1200+600)?

A common adjustment is if you claimed the Recovery rebate credit on 1040 line 30 when you already got the Stimulus payment or got the second one after you filed or reported the wrong amounts or entered them in the wrong box.  Line 30 is only if you didn't get them or qualify for more.

If you claimed a missing stimulus payment on your return but the IRS took it off you have to ask the IRS. They think they already sent it to you. Maybe it went to an account you don't remember. Or you got a check or a card. It was probably easy to miss the debit card in the mail and think it was junk mail. They have to put a trace on it.

How to put a trace on a missing 1st or 2nd Stimulus payment.  IRS for Payment Issued but Lost, Stolen, Destroyed or Not Received

See question F3 here, you can expand it to see how to put a trace on it.

https://www.irs.gov/newsroom/2020-recovery-rebate-credit-topic-f-finding-the-first-and-second-economic-impact-payment-amounts-to-calculate-the-2020-recovery-rebate-credit