Yes! Get to the bottom of things right away.
Once a collection place tried to sue my son for an unpaid CC bill. Went to court and they didn't show up! The judge talked to them and told them he had proof the bill had been paid several years before, and (not these exact words) he'd have them arrested if they ever tried it again!
I know they were paid because I paid them for him and had my canceled checks to prove it! HA!