Unsatisfied client

I bought a new flat, and unfortunately for me, on the very first month, my tenant got in, he was affected by a geyser burst, fortunately it was still under warranty, I called heat Tech Geyser, they allocated TN Plumbers to evaluate and advise. It turned out to be geyser burst, and they promised to replace it, they called me saying, they don't have stock, they will have to order one. My tenant is staying without a geyser in Winter, I called them again and they still responded with the same reason. I feel like they are not expediting it because it's not a sale. They should not rely on one supplier, geyser is a necessity in Winter. Ref no. Was SC83640