MrP Mobile do not take contract with them

This phone department for Mr Price is full of s**t, I took a 24 month contract with them and towards the end of the contract they called n want me to upgrade or renew the contract of which I decline their offer. Two months after contract ended, they debited my account double. I reverse the amount, before calling them they called saying my account is on arrears, I was like which account now cz my contract was 24 month, they told me some stupid explanation saying I should have write a cancellation letter and send them. But when they wanted me to upgrade they did not tell me to write that letter as I said I dont want an upgrade. I write the letter, n they tell me they can’t cancell cz m owing. Paid the amount said, after 3 weeks they calling regarding my account. Please good people if you want peace don’t ever do business with this company, they don’t know what they doing. There are bigger n reputable companies I’ve been taking contract with which ended the contract when it’s time has come not this stupid one with agents not knowing how to do their job.