Guesthouse Owner reluctant to pay for services renderd

I have been dealing with the owner Debbie Ponyec. She made a booking at our establishment on behalf of her client. She then made a deposit on the invoice sent, even though an invoice for the full amount was expected of her for payment. It was also confirmed that the client had paid the full amount to her prior to their trip to Cape Town. Two months later we have not yet received payment for the outstanding balance. Numerous emails, phone calls and messages was sent to her as a request and reminder to pay the outstanding balance of R 19 600.00. Debbie has given us every excuse possible but no positive outcome to date. She can not be trusted and her word doesn't actually mean a thing. I would not suggest doing business with them as they do not care to misuse other establishments where full service was given to the guests and shedding a bad light on themselves ( Sunset Beach Lodge and Spa) .