Billed for 3Gig instead of 1Gig mobile data

This is my second complaint this year. I call this a total rip-off. How come am I being billed for 3Gig mobile data if I am on 1Gig top-up (cell number: ***). I am very disappointed by your poor service. And I am tired of making phone calls to complain to you. Can you please just cancel the whole contract and I will pay cash for the device. A few minutes ago I was talking to your consultants, explaining my frustration, instead of helping me, she decided to drop me off. What kind of service is that.<br> <br> I need urgent explaination on this please.