CellC Fiber

After weeks of emails and calls I am still waiting for CellC to get back to me with some geedback/resolution. I signed a fiber contract for 15/15, I am lucky if I get 4.8! I cannot cancel and move to anothet provider as I signed a contract. But if I signed a contract should I not get the service offered in the contract? I you cannot offer me that service, surely you are in breach of contract??? Why should I pay you??? My mobile data workks 100%. What is wrong with your fiber? Can I get some type of sercice or can you cancel my contract? I would love service!!!!!!