Two fautly gas heaters supp**** - no refund

I bought a Gas Heater, make is Zooltro on Groupon Website for R2699 for 20 lt - it stipulated that it must be installed by a certified provider. We paid R1800 for the installation and when the installer switched it on it leaked. I lodge a ticket on 29 September 2015 with Groupon (ticket no ***5) explaining that we are without water since the gas heater is leaking. They informed me that they have a 72 hour turn around time not understanding my emergency. Eventually they send replacement, but this one was not working either!!! This is after I had to pay again R1800 for installation!!! On 2 October I still did not receive any solutions from Groupon and I had to purchase another make Gas heater in order to have warm water at my house. I decent brand Atlas gas heater costed me R6000. They arranged for the defect gas heaters to be collected but to date I have not received any feedback or refund. I would advise all people not to buy gas heaters through Groupon and especially not the Zooltro make. I need to know when I will be refunded for the 2x installation cost of R3,600 plus R2,699 for the gas heater. No proper feedback are given by customer service. Please help! Tanya