Worst service provider ever

I have received the worst service from Cell C ever and they’ve made it nearly impossible to use my phone at all or run my business!? I took out a contract for my phone and a router with data to use at my studio to stream mysic off of. Meanwhile they never told me that with this contract I can’t load any airtime/data if mine depletes. Not even 1 week in all my data and airtime has depleted and it took more money off of my account. I use wifi most of the time and I’ve put all my apps off and mobile data when using the wifi so it is impossible that any data was used?! Besides that, the router has less than 0% signal at the studio and when I phoned them they said no they have a lot of signal in this specific spot, I have phoned numerous times and it still hasn’t been resolved, and having a phone that doesn’t work made it impossible to phone so had to borrow someone’s to phone the whole time. My premium goes off every month and now my network has been off since last week Saturday. Making it impossible for anybody to get a hold of me. I went in today and they told me my sim is faulty and it will cost me R150 to do a sim swop which is the only solution?. I am sick and tired of Cell C and the pathetic service. I want to cancel everything ASAP and move to a different provider!!