CellC Breach of agreement and services delivery promise

Good day. I am very unhappy with what i got. As i got a wifi package from CellC online for 100GB data with the cell c router ****9 p/m witch only worked for the first month and then no internet access! I've been battling with CellC from the 25th of April and still they couldn't resolve my problem or help me in anyway. I've opened 4 case's with them (of witch 3 of the cases apparently just disappeared) and still no feedback, after every time i call they say they will contact me back, but still haven't. And every time i call they can't give me an answer. Apparently there is a problem with LTE service form CellC's side. But they can't cancel the contract and they can't help me with a migration to a different package. So why must i keep paying for something that i can't find any benefit from. Why must i pay but they can't keep up their deal.