Cell C holding me hostage - won't let me cancel my expired contract

Cell C still won't let me cancel my contract - Last week after posting a HelloPeter review, Cell C contacted me once with two calls directly after each other at 7:36am, I was not lucky as I was driving at the time and so could not take the call, but they promised they'd call me back later, A new week has begun, it's already halfway through this day and still they didn't call back, They only responded on HelloPeter site with a comment that I was not reachable, I even called back the same day and I reached a Nomphumelelo who told me, they don't give out surnames according to Cell C policy, she tried to shift me one to the department who apparently had tried to call me, but said they were not responding, I told her they cannot keep passing people off from department to department, she ended up just saying sorry, can't help she will escalate my issue and tell them I called, then I must stay on and review her service! Frustrtaed