Unhappy service with Bonitas

I had an account with Bonitas which I discovered was due to the doctors submitting a medical form completed for another medical fund and Bonitas paid for the consultation. Subsequent to that I then paid Bonitas in November 2017 half of the amount owing. In the meantime Bonitas submitted this account to a collection agent by the name if CWX. I then paid the collection agent the balance owing in full on the 28th February. Between Bonitas and CWX, they have not been communicating with one another. I keep on receiving a statement from Bonitas showing the amount outstanding which was paid to CWX. In the meantime I have been harased on daily basis from CWX requesting the money paid directly to Bonitas. When I explain to the tele staff from Bonitas that this has been paid I was told to send proof if payment which I have done. To date I am continuously phoned by CWX which I might add they keep on telling you that the call is recorded and I am convinced that no one listens to as the calls keep on happening. How long and what does it take to get this matter cleared. Bonitas always relies back to me that the financial department is handling this. SERIOUSLY SINCE FEBRUARY??