Russells and sagging chairs + BAD SERVICE

I bought dining set at Russells Bloemfontein, just after week all 6 chairs were sagging. Went there to complain, they fetched them and took almost 9weeks trying to fix them, then after fighting with them they gave me new ones. After a week again same thing happened, they were sagging. Went to complain, told them to collect their dining set and refund me. The manager there told me he will call me after addressing the problem with his superiors.. Its been a month now waiting for their call. I want my money back