Guys at steenberg tyres buys in tyres appliances and gold

Guys at steenberg tyres buys in tyres appliances and gold. they bought a pearl chain by me with 9ct gold clasp. then on wednesday 4feb they bought my 9ct gold earings too.the deal was that they fetch it at cash for gold and pay me the difference.i asked to be paid via eft because i needed to be somewhere.they only sent R500 claiming that they needed to put in fuel and that they will send the remaining R200 the following day.its saturday 7feb and still nothing.they dont reply to my msgs and they wont answer my calls either