Not able to refund for a faulty machine

Wife and i rented a carpet cleaning machine from Levingers in Mall of the South the person helping us showed us how the machine worked then he switched it on to say it is working, so we paid the rental in full plus a deposit on the machine, went home and we tried to use it but there was no water or soap coming out of the machine. So we decided to call the store but no answer so we tried the Rug Doctors help line but they were not open over the weekend. So we took the machine back to the Levingers store in Mall of the South and said to the guy it was not working.He tested it and it was not working then he saw there was a pipe not connected properly to the machine once he connected it, it started working at this time we were so frustrated that we said that we want our money and we are not going to use the machine because of all the hassle. they said they cant refund the money of the machine but will give the deposit back, on top of that the store person said that \how does he know that we have not used the machine to clean the carpet already and now asking for our money back' I was not impressed. It was actully his fault cause he did not check the machine was working "