MTN Staff are RUDE & wont Blacklist my lost phone

It has been 2 weeks now that I have been trying to blacklist my lost phone with MTN, each time I am told it will be done and I must call later for a ref number, when I call a day later I am told it wasn't done but now its done. The staff have stinking attitude on the phone and are not friendly or helpful, makes one wonder why they are even working in the first place. This morning I spoke to Noncokolo who told me she couldn't blacklist my phone because its a contract phone (Which in the 2 instances I called 173 it was never mentioned to me) she was going to put me through to contracts department, when she put me through, I got a voice recording telling me the number I dialled doesn't exist. I am tired of begging MTN to blacklist my ****** phone, what does one have to do for this to be attended to, what is the point of saying you offer a service if when one requests it, you don't even bother to deliver? This is disappointing, I have a contract with Vodacom, my sister is with Cell C and we have never experienced such professionalism and disgusting service!