Very poor service by service centre

I had lodged Venus water heater service request 1902090295 dated 9/2/2019. Request was done for general service of water heater and appliance was working properly. Flow of water from tap was slow. They took my 2 water heaters to their local service centre in varanasi. And now they are not giving any response regarding my two unit of water heater. Worst case of customer service. Harassment by the local service centre. And this would be loss of goodwill of venus company which is leading co. In its sector. Untrained staff and poor management.