Unhappy on service provided on applying for medical aid

I recently took medical aid cover -momentum via optivest the cover was only supposed to start beginning of August , but my account has been debited even before the cover began from the month of June ,July I have had to reverse the 1st debit order that went off via the bank,now I have been debited twice I called momentum ***to find out what is going on and they said they can't find my info on the system and they will call me back in 15minutes which has not happened. I was charged a fee of R89 by optivest I am extremely unhappy about the service, the fact that I have to reverse the debit orders and the fact that I'm paying twice for the cover which has not even begun I need answers from Optivest