Bad bad customer service

Bad service My dad & I went for a test. My dad paid cash of R1400 in Oct 20, upon the lady said she would e-mail me the receipt. Up until today with numerous calls, and visits no receipt. They promise to phone. My glasses was confirmed saying that I don't have to pay anything, but couple weeks later they day there is an outstanding amount. The lady even said she cannot process my glasses if there is an amount I have to pay, they why????