Poor Workmanship and service

Bez Loodgieters checked a leaking geyser and we received feedback that the geyser was installed in 2006 but the element, thermostat and seal needed replacement. We were informed that the cost would be R1850.00. They requested 80% deposit before work would commence however we paid in full. The components were replaced on Friday. Late Friday afternoon I received a call from Bezuidenhout loodgieters stating that the geyser now needed to be replaced. I was told that if an old geyser has new parts inserted that there is a 98% chance that the geyser will blow. The body corporate uses a preferred plumber who eventually came to replace the geyser and immediately stated that you could see it had rust marks and had been leaking for some time. It had burst and Bez would have seen it when they went to repair and should never have continued with replacement of parts. Bez is now only wanting to pay back R623 back from the original amount and only after we have removed and returned the components. We can't see why we must pay for components that never worked, the geyser should have been replaced and not repaired. We would like a reimbursement of monies paid and Bez components removed.