DO NOT USE STD BANK INSURANCE- TOTALLY ***********

My geyser burst & was replaced on 21 Jan 2019 by a Std Bank insurance plumber. From this date boiling water constantly pours out the overflow pipe into the garden in extremely large volumes. It has been reported to Std Bank Insurance as well as the plumber who did the installation. The Std bank plumber maintains he can do nothing because it is the manufacturers responsibility. The manufacturer, Duratherm sent out their plumber on 3 occasions. All he did was change the thermostat 3 times. When questioned that is wrong he rep**** that the thermostat which his company uses is not of a good quality. We are terribly inconvenienced. In the interim boiling water still pours constantly. We called Std Bank over 8 times to report this. This call is normally answered after 20-25 minutes because of the high call volumes. Then we have to hang on for another 6 - 10 minutes whilst they get hold of their service provider to verify. Problem not yet resolved. Losing about 150 litres boiling water per day. Taps are also getting damaged. Water loss is high. Have videos and photos of these incidents. Extremely frustrated that after 12 days the problem cannot be fixed. Today we got hold of Duratherm and was told that the plumber is not from them but from a company called ITU. My issue is why do I have to deal with all these *********** service providers? Please assist urgently.