Bad service now my account is deactivated without my knowledge while they made a promise to call me back before they do but never did

My concern is, I'm having price lock with multichoice which expires this December, now they keep on deactivating my services and sending me sms that says I'm owing 4000 from previous unpaid fees which I have no idea where all this amount accumulated and I don't understand why didn't they deactivated my services then than now. Since I wrote to you peter they promised to call me back which they never Did, now they are taking advantage of me because I'm desperate of watching tv. This is bad all I need is for them to tell me the facts cause I have been paying all my premiums monthly please help