Masterparts kenilworth bad service

Bought a set of pistons and rings only to find out that the rings is a problem. After multiple calls this still hasn’t been sorted out by them. Not once did they get back to me. I had to call them everytime and my engine block was worked on according this piston. We’ve asked them for help several times but to no avail. I am now having to import rings that are worth more than the pistons and they still didn’t contact me with any help whatsoever. It’s now costing me way more than the budget put out for this rebuild. This extra cost should fall on them for not supplying the right parts. Clearly they selling this particular brand and should be able to rectify the situation