A poorly run SCAM or an exceptionally incompetent ...

A poorly run SCAM or an exceptionally incompetent company that keeps making mistakes as others have mentioned before.
Highly suspicuous nontheless for a "Debt Collection Agency" if they can even call themselves that. Not that one has to achieve a high standard to get that title. Mostly ex criminals work as debt collectors as they enjoy finally having found a legal grey area of devoiding people of their belongings. Be very careful with Advantis.