disappointed and sad with MTN big brand but poor service

I'm deeply disappointed with MTN they are quick to assist with the contract and when you provide with the banking details, they are quick to process with the application but when they need to debit, they don't, then quick to send threatening and demanding letter and be escalated to the lawyers to be blacklisted. i called mtn to make arrangement then spoke to a consulatnt by the name of Khanyezi mcunu which i never received any joy i asked her to ask me other questions as i failed the one she asked, but she never even tried to give other options for me to be assisted. it a huge a company but has no empathy even sympathy for client based on what they are going through i will never ever again take a contract with MTN cause their service is very poor! i am so angry i cannot even explain how angry i am.