Bad service

They offer the worst after service purchace. I bought a unit in April, the top of the range unit and paid them to install it. Now my unit is not heating up and i have called on Friday 14/08 to let them know and completed a ticket form, twice already. First Jack from the complaints department said he would call me in 10min, which did not happen then he said a technician will be in the area by me on saturday and they will call me. Monday i called and sent whats app's which they did not reply to which at this point i was boiling for the bad service and extremely irritated. everytime when i called i indirectly got the middle finger and was told to wait when they will accomodate me and will not go the extra mile to assist after i have been without hot water and calling from my cell phone. they refuse to let me speak with a manager