Lies on services provided

I am writing to share my review of MTN's ridiculous services. I have a cellphone contract with them. In March, they billed an amount that I was not used to. I was given a data sim card from the service provider, who did not disclose truthfully how it would affect my billing. I questioned it and was told that, upon their own investigation, they were aware of my case. We concluded it by requesting closure, which would take 10 days starting from the beginning of April. Till now, they have not closed the SIM card and have sent me a bill that is ridiculous for a cellphone contract that is expected to end in less than three months time. I am honestly sick and tired of this company and its tricks to continue billing me. I am so unhappy, and when my contract comes to an end and I will never take out anything with the company. I have had enough, They are a bunch of ****s.