Misleading marketing of ePromo aircooler system

Background: I bought a Briza air cooler at the outdoor show at Midrand on 22 Fenruary 2020. I specifically asked the salesman whether the system will cool my caravan during summer when it is closed and he confirmed that it will. I went camping in March and established that the system do not cool the caravan when the windows and doors are closed and requires natural air. The system therefore do not serve its purpose and I reported it the week after our camping weekend. I was told to return the unit to your offices and request a refund as the unit do not meet my expectations. I subsequently contacted Glenn Green on four occasions being 5, 23 and 30 June as well as 8 July 2020 as I have not heard from them again nor received my refund. I found their service unacceptable and just want ePromo to refund me as explained in my e-mail messages to them