I made a telephone payment on 9/8 they are now saying my payment is overdue!!! What happened to my payment ?

What happened to the telephone payment I made on 9/8/26? They're saying my payment is overdue. It was due on the 8th. The man I spoke to said he had my checking account info. Said I would get confirmation number but I didn't! I have had a lot of trouble paying by mail, I received my bill just three days before it's due. I had auto pay but that didn't work, it wasn't taken out for 2 months!!! What's going on!!!