Poor service

I paid my account at mtn shop as usual. The person who helped me realized later that he didn't type my number correctly the last number was not correct. He immediately sent an email asking them to allocate those funds accordingly.They never sent an answer. Instead they closed the ticket without communicating with him.I then wrote an email myself. They received it and told me to send them my information and I did. Three days later they told me that the matter was resolved. But they didn't allocate the funds accordingly.Then I tried to send them another email but they told me that the ticket was closed.Now they are sending me messages and calling me reminding me to pay. Yes I will pay it cos it's my account. I very much disappointed by them and I think this is my last contract with them