Billed for a service

I did my upgrade at the Stellenbosch brunch in January 2014, The spesial that was part of the contract is that a will received 500mg of data free. It come to my attention that my data was very high and when i go to the Stellenbosch branch to found out what is happening - they informed me that Autopage never activate the 500mg on my contract, instead they were charging me for EVERY MG of data - that amount to about R2000 over a years period!! i have locked a compline in January already - we are now in June and did not have a call/ an email nothing from then. I call them again with my ref number and they informed me that nobody have touched the complain in 26 days? can it get worse????