Time-Freight battles to pay R900 odd rands from March 2020.

I have had an account with Time-freight for over a year, ***, to which I had paid more that what was due, I have not used their service for at-least 8 months due to a past bad experience. I have not since March 2020 been trying to get a refund for the R900 odd rand surplus on my account, to which I have now been send from post to pillar.

Yesterday I received a June Monthly statement, indicating that I have been paid and the account is R0.00, which is not a true reflection of the account status as no payment has been made.

We are now starting a 4th Month of battling for my R900 and it isn't just a nuisance but a waste of time chasing R900 which their account department seem to have squandered judging by the incorrect statement.

What else must I do to get my money back from this thieving company?