Handed Over - non payment?

I was a Bonitas member up until December 2014 whereupon I moved to Bestmed. . In February 2016 I received a sms from Creditworx stating I owed them money, which I ignored. Two weeks later I received another sms which prompted me to call them. A call center agent told me I owed Bonitas money which made me call Bonitas, I spoke to a call center agent at Bonitas who told me that I there was no money that I owed them but they would get someone in the accounts department to call me. Since then no one has called me. Today I got another sms from Creditworx.. Whats is happening?