Complete lack of customer service

I bought a UPS from this store Tues 3 Feb but only got round to connecting it to my computer on Sun 8 Feb and it did not work at all. I took it back to the store at my first opportunity on Wed 11 Feb. They tested it on one of their machines and it would not work but to make sure the battery was fully charged they kept it on charge for the afternoon. They promised they would phone the following day with the outcome. By Friday they had not made contact so I phoned to be told that the unit was faulty and would be taken back to the manuf/supplier for repair. I asked why I was not being offered another unit as it had been proved they had sold me a faulty unit. I was told that only the owner could make that decision and he would call me. Despite further phone calls and my wife calling in at the store I still do not have a unit and the owner has not given me the courtesy of a phone call. They sold me a faulty unit. One would expect them to take the matter up with the manf/supplier & look after their customers by immediately offering a replacement. No customer service whatsoever once the sale has be made.