Service Interruption and Poor Voice

I have been a loyal VC customer since 1993/4, when cellphones first hit our s****s. Right now I am looking to terminate my 21 year contracts (mine, my wife's, my daughters and my son's) because I cannot get proper service in my area. This relates to voice and data. Calls drop, conversations are inaudible, 3G is slower than dial-up and frustration at this point is simply not worth the effort. All residents in my area complain about this and it is not specific to my location. Over the past year it has got progressively worse to the point that I will try MTN, 8TA and CELLC just for a glimmer of hope. My suspicion is around bandwidth, delivered from Telkom, is causing this - as there is a direct correlation to the degradation of my Telkom ADSL service and the Vodacom service.