Shocking backup

I had my burst geyser replaced by a Durotherm geyser. After 7 days the element blew. The plumber who installed the geyser had a look and informed me that the element has to be replaced by Durotherm. Well good luck with that. The call centre never gets back to you. Their plumber is always on his way to you and never arrives. After 5 days with no hot water I got the original plumber to replace the element and still no word from Durotherm, even after another 4 days.