double pmt no refund

Went in to dry clean a suit and settled in cash. Supplier did not contact to collect and so i phoned and had someone collect. They made that person pay again at a higher price. I went to get the second payment back with proof of slip. They said it was only a booking slip. I asked them to check their accounts but they cannot trace payment. I know i paid. It was R185 so not like i am ripping them off but i know i settled and they know it 2 but owner wont refund.