Worst service provider ever

On the 8th November 2013, I took a contract with Nashua Mobile. Each of these headsets cost me R140/month and I received R100 airtime, 25 SMS and 300MB data. I paid R280 for about a year ****il October 2014. When Nashua Mobile went under, my contract was transferred to MTN and since the change over from Nashua to MTN in October was billed R438 for exactly the same product. I reported this to MTN Somerset mall service center in December and the consultant I spoke to is Daneel Malgas. He promised to have it sorted out. I got the same amount of R438.00 deducted from my account end of Dec, January and February. Things took a turn for the worst in March when my account came out to be R596, for the same product. So from end of March, April and May I have been paying R596. Over this period, I went to the service center in Somerset Mall countless times( I was attended by Madoda, Daneel and even the Manager Steven) who were all promising to get this rectified. I also wrote on the MTN facebook page, on Hellopeter (Kagiso Kekane responded asking me to send documents). I have complained to head office, Farzanah Kariem (Escalations), western cape MTN, but no one is helping.