Migration of data

Good day,<br> <br> Last year I subscribed to a 500mb data package, I was assisted by Ernest and he explained everything to me. I was satisfied. He told me that I can make changes after 3 months if i feel it is not enough. And from Feb I've trying to change to 2gb but no one is willing to help. I've been dropped, xferred and given number to phone, I even went to the shop but still no one is helping me. <br> <br> Thanks.