ABSA Insurance fixed the geyser but the problem still persists

In April this year we had our geyser replaced about 2 weeks later when opening the taps a loud thundering drumming sound would come from the roof. my husband then logged another call and after 2 weeks they sent enough guy to come have a look but he could not fit through the trap door so nothing was done. We then logged a complaint and eventually after many many call and no satisfaction I posted on Twitter/X and a guy called Aubrey called and after a long argument and explaining finally they sent another plumber. these guys then went up and checked and put in about 4 clips to stablize the pipes. we then though it was fixed but to our surprise it was not. we then got a all from another guy to check up on our complaint and he said he would sent out someone to come have a look... thill today no one has come. We then received another call from a lady this time who said exactly the same thing... till today no one.

so with all the above I want to know why we now have this problem after replacing our geyser cause we never had this problem before cause surely the plumber who replaced the geyser should have check whether the plumbing in the house is suitable for the new high pressure geyser.

This problem is now becoming EXTREMELY annoying as I we have a 6 month old baby and a 70 year old women in the house and when we get ready for work at 5am in the morning this thundering sound after we have showered wakes everyone in the house as it lasts for at least 3 - 5 minutes at a time.

SO ABSA INSURANCE I WOULD HEREBY LIKE TO GIVE YOU THIS WEEK TO RESPOND AND GET THIS PROBLEM SORTED AS I WILL NOT BE MAKING ANY CALLS TO YOU AGAIN, THE ONLY CALLS I WILL BE MAKING IS TO CARTE BLANCH AND THE DAILY SUN.

IF YOU NEED TO CALL PLEASE CALL *** OR EMAIL ***

THE INSURANCE IS ON MY MOTHERS NAME BUT SHE IS NOT FIT TO EXPLAIN THE SITUATION TO YOU SHOULD YOU WANT TO SPEAK TO HER IN MY PRESENCE YOU WILL NEED TO CALL AFTER 5PM