Telkom sales staff don't know what they doing!

I cantacted telkom's sales department last year October to get prices on upgrades and was given prices that never materialized on my bill! I have logged the incident 3 times and also spoken to managers to no avail, my line was now suspended due to me paying what I was quoted and not what they wanted to charge me! I cantacted the person dealing with disputes again twice but still nothing gets done about the problem and they don't even bother getting back to you!!!!