Blake and Associates Poor Service and Harassment

I have been harassed by Blake and Associates for the last few months now, they claim that i cancelled my Telkom account prematurely, which was not the case. I send them all of the info that prove that I cancelled the Telkom account months after it expired and even gave them the order number for the contract and cancellation number. I spoke to Telkom various times and they confirmed this. About 10 people from Blake & Associates have called me about this and every time I explain the story. I have sent various emails to both Telkom and Blake and Associates which does not get answered or acknowledged. I am at my wits end and feel totally harassed with this company. I ask to speak to management but then get told that I can't. I asked for other email adresses and then get told that there are none. It is just a black hole. It seems that they want to drive you so crazy that you just pay the amount even though it should not be paid, just to get them off your back. This is shockingly bad service and if I am Telkom, I would not work with them. I pay thousands every month to Telkom, but feel like cancelling all contracts, just to not deal with Blake and Associates.