bad service

I had purchased a hawei wifi modem for R159 per month. 4gigs at night and 3 gigs during the day. When I had gone I store today I found out I need to pay R2739.67, I'm unhappy about the fact that Sandile Ndaba didn't explain the T&Cs that apply with the wifi. I asked to speak to the manager today and the manager was not even interested in coming to speak to me(Tisetso Selikiso, the storemanager) The consultants should make sure that I am happy before I leave the store and to be honest with the contract that I purchased! I am VERY HAPPY that i cancelled my contract with cell c!! I will never refer someone to go to cellc as i recieved bad customer service!!!!!!