GEMS did not settled all payment for my operation

My wife was admitted to Tzaneen Medclinic on the 05 July to 06 July 2018, pre authorisation was done earlier. the operation went well but to our surprised we received calls from Medclinic that there is an amount of R3220.00 that should pay before the 07 December, otherwise they are handing us to Credit collectors. they are saying GEMS did not pay them for one of the device they used during operation. the details of the machine they used are as follows product Code RTLC2-ENTNERVEMONITOR, Description ENTnervemonitoring. The operation was for the right ear. According to Hospital and Doctor this machine is very important when doing operation because it monitors the nerves . please assist, we don't have money to pay the hospital