Poor communication and don’t get why I still have an outstanding amount when I paid fully

They say I have an outstanding amount of R1311 where as I paid my first instalment of R1311 by Ozow in a link they send my me by sms then they deducted their last payment of R1311 by debicheck, I don’t understood what the outstanding amount is for and I’ve been trying to get in contact with them they’re not responding to any of my emails and their number for calls doesn’t go through