No signal with Cell C

I've been a Cell C customer for almost 2 years now. Everything was relatively ok until I lost signal recently. My data stick disconnects every 30 seconds!! And I have 3 lines with Cell C! I contacted their helpline about 3 weeks ago, and they explained to me that the tower in my area needs upgrading. Recently I left a message on their website, explaining the whole situation, but they never return a call or contact you - ever.<br> <br> I want my contracts to stop with immediate effect and I want to be reimbursed for all the data I couldn't use!