Troubling service at a major service provider

<p>I settled my account and received a email to that effect on 2016-07-13. I requested a total canellation of cell nr and account. A year later i get a invoice stating they owe me R2480 and was billed R687 for the same nr, i enquired and sat for 3 hours from dept to another and was told it had to be forwarded somewhere for the reimbur*****t to take place. I returned their call on 2017-08-07 and was disturbed to hear that i had been billed twice again and that the account is on nil. I have been through different departments and there is no resolution whatsoever. Maybe they would like to be sued after this if they take a debit order from my account?????</p>