After you file

Yes, did it all and sent it certified mail.  Tracked it a week later and it said it had not been delivered and UPS would attempt a later delivery which finally was successful.  Apparently there was nobody there on the Friday they initially tried to deliver it.  Without a signature I guess they would not leave it.  However, it has now been 8 weeks since I have tracking proof that it was delivered...but the IRS has not cashed the check yet!  How is this possible?  And, my amended return is not showing up on their tool.  What concerns me is if whomever received my return has trashed it or lost it, unless the Covid 19 issues have held it up, but why is it not showing on their tool as received.  PS.  I never received the return receipt that I paid for when sending it.  Who can I call?  The number they show for the tool is automated and gives me no information.  Please help as this was a large payment we had to make and interest is accruing!!