Over charged & not being refunded

My name is Sivuyile Zantsi ID# *** cell# *** email : ***. I was over charged when buying my car at Webuycars Germiston in July 2025, I was not aware of this until my salesman (Ismael) called me and informed me I was due for a refund of R850 that I had over paid apon parchasing my vehicle. I've sent them all documents they've ask from me, I've sent numerous emails asking to be contacted by a consultant who can assist with this matter and I got automated responses telling me I'll be called soon and never called. Today I sent the salesman (Ismael) a WhatsApp & he said my refund has been declined. Please get someone to call me.