Dissatisfied and irritated due to false advertising

I'm very disappointed with multichoice because they are constantly deducting more than they're supposed to be deducting on my account. I upgraded to compact plus due to an advert that they did stating that if you upgrade to compact plus you will only be paying R460. But to my suprise after I upgraded I checked my premium on their site only to find that its going to be R675. I called their contact centre and they promised to fix the error and only deduct R547 due to the fact that I have extra view and insurance, they even sent me an SMS confirming that but now to my surprise when I checked my statements, it shows they have been deducting R675 ever since. This I regard as false advertising and misleading of customers, I'm tired of liaising with the contact centre and I wish multichoice can just fix this as soon as possible.