Account handed over without clarity

In 2015 I had gone to park lane for a delivery. I paid the booking fee of R350 in May via eft. In July I gave birth. About 3-4 months later I started receiving emails from Lerato Tloti about an outstanding fee of R350 I Asked Her for clarity on what the R350 is for and all she can say was call your medical aid. February this year I get a call from a collection company about R350 I owe I ask for clarity and they too don't know what it's for. So I then contact my medical aid and they say they have no record of me owing. I call Park lane accounts department and speak to Kedibone who tells me I didn't pay a booking fee. I explain I have via eft and can email send her a proof of payment. I sent the the proof of payment to both Lerato and Kedibone and the only thing Lerato could say was contact accounts department. I've been trying to contact both of them and there's no answer on they direct line. I also got a letter saying I'm now listed on the credit burea for a payment that I made last year. It's really unacceptable that no one is answering their phones or getting back too me about the fee.