Handed to ITC collections

I have been informed in January 2015 by Lancet Laboratories that my medical aid has not settled an amount of R837. Thereafter I made regular monthly payments on the following dates : 29 Jan 2015, 23 Feb 2015, 25 Mar 2015 and 22 Apr 2015. On 22 April I received a sms informing me that my account has been handed for collections to ITC. I have not received any correspondence from Lancet Lab informing me of any cut off date that I required to settle my account. On 28 April I received a telephone call from Linda Reddy from ITC informing me of my unpaid account. I was also informed that the cost of the telephone call will be R19,38 which will be added to my account. Further to that my total handover amount was R569.91 which an additional of 11.4 percent will be added to my account. I humbly request Lancet Laboratories to rectify this error urgently and have my name struck off ITC debt Collectors.