over charged

i went to Tieho to take up a new contract and it was suppose to be on a top up and later i found that he did not pout it on the top but it was on the open line package and when i went to him to ask him he said it was the MTN system that charge it he captured correctly and now he wants me to pay for his mistake which i does not acknowledge and i went the to compliant and he cant sort anything and its been 3 months now and he keeps saying he will tell his managers but nothing and am not going to pay that amount he will pay it .<br> his service is very poor and i would not recommend anyone to go the Glen branch their service is bad and beyond