Worst Service Ever!!!

I went in to upgrade my contract in the first week of Nov 2015. I told the consultant that I did not wish to change my contract and wished to stay on the Any Time 350. I was told that the new Sim card would be activated between 2 - 24 hours. 72 hours later it still wasn't activated. I phoned the branch where I got the contract and they said oops something had gone wrong and they would sort it out. Finally, hours later it was sorted. Then 2 weeks later I noticed that I wasn't receiving any data. I phoned again, and they said it was a mistake and they would sort it out. Then I noticed that I had lost all my accumulated airtime which I very carefully monitor every month. I phoned again, and was told that by upgrading my contract, I forfeited that amount. I was furious, as if I had been told that, I would not have upgraded at the time. I phoned 808 and was told the same thing by another consultant. Last week Tuesday, I phoned again for a small problem I had, and spoke to the first consultant that was helpful. She said I should NOT have to forfeit my accumulated minutes and she would put in a query. I have still heard nothing. I want my contract cancelled!