Leave me alone! You owe me money!

Hello MTN

I cancelled my wifi with you weeks ago! I am waiting for my R1606 refund!!! And you send me this ???? Y'ello! You've agreed to pay R 438.25 for 1 DAY from 16/09 to get your MTN account up to date. R 438.25 is due today. Pay in-store or via your bank. and use billing profile BA*** as a reference. You can find the banking details on your invoice. Please leave me alone!!!!