PACKET SWITCH DATA

I have had my MTN cellphone contract for as long as I can remember. I have had many problems and queries, but I can usually get answers from MTN.<br> I have just renewed my contract with MTN and opted to take a Data contract only, as I have a second cellphone that I use for calls.<br> My contract was for 2GB Data per month with 2GB data free at night time...<br> When I received my August account it correctly showed the subs fee (it also showed an amount of R11-34 for packet switched data calls- which I stupidly did not query then as it was minimal). <br> I have just received my September account and again it shows the correct subs fee BUT THIS TIME it shows packet switched data as R387-35 - firstly what the heck is packet switch data. I am using this phone for simple things like purchases through online stores such as [URL Removed] some news, some whatsup and that is about all. No-one else uses this phone and I am not linked to any other devide. I am furious as this is not what I asked for. In actual fact when I took out this contract in July I specifically told the salesperson at the MTN store that I wanted the limit set to 2GB data only. HELP .... CAN I CANCEL THIS CONTRACT??