Best answer by Ismail.koodo
The offer for $15 credit is available for the first 12 months only, that is the reason you have been paying $5, after that you start paying the normal rate!
Here is what is says on the Nitty Gritty on the website : '' Limited time offer. You'll pay $5/month for the first 12 months. On month 14, you'll begin paying the regular price, currently $20/month. ''