Packet switched data calls

Good day can someone please help I am very frustrated , I have my mtn account in for ever but lately I have notice a change in my 2 accounts by almost R2000-00 per month for \packet switched data calls"I did not asked for this sevice and I have complained but still they deduct this money . I did not give mtn permission for this service . They have been deducting this for 3 months and I want my money back and how do you charge \""packet switched data calls\"" on a iPad . I have google this and it's to keep your internet live while making a phone call. <br> I did not ask for this service can you please help me .<br> <br> Thank you <br> Very frustrated client """