Passing the buck

On the 7 March 2015 I needed ambulance service to take me to hospital and an ER24 ambulance was called. The company than claimed R1703.30 from my medical aid which was paid in full. A statement by my medical aid was sent which showed payment for services of this company. To my surprise on the 2nd of October I get an sms stating that my account has been handed over to nuDebt for collection for an amount of R1110.80. I immediately go to my medical aid offices to query this so called debt, they tell me that the amount claimed by ER24 was paid in full and as I showed them the sms, they inform me that they cannot authorise payment for something that has not been claimed by the service provider. I then called nuDebt who I must say are clueless and kept telling me about the amount am to pay and kept saying my medical aid did not pay full amount. When I asked about the R1703.30, they had no idea of what am talking about. ER 24 has never called me even nuDebt for that matter and now they are busy threatening me with being black listed.