Horrible service

I app**** for fibre in March and received awesome service, up until 3 weeks ago. I was promised 3 months for free, which means my first payment was supposed to go off at the end of June. They have now taken R1878 out of my account. 3 weeks ago when i noticed that the payment due was so high, i contacted customer service immediately. I was told that they can see the 3 months for free, but they don't know why it charged the amount. I have spoken to the salesman who promised to call me back, which obviously never happened. After a fb complaint someone from head office called me, and promised someone will call me to sort this out. That obviously also never happened. I am appalled at the service received. I will be canceling the fibre and also my cell phone contract with Cell C.