Poor customer Service

I bought lounge suite cash, they didst deliver on time...when they did it was a wrong item in terms of color i asked they to take it back...they came back afterwards with right color but one unit has rust on it which shows it wasn't brand new....i reported the matter same time, they did apologize and promised to change the unit later one they told me that they will repair the unit and i refused because i bought cash for a new unit now they don't say anything not taking my calls basically they don't keep their promises they don't bother to phone....it seems as if once you pay they they don't care afterwards i am very disappointed with their service because their product is expensive i was hoping for a good service....i Need help if they can not change my unit i want my money back