Bedroom suit

I bought bedroom suit cash and the delivered the damaged one while I was aways but after finding out after a 2 weeks and complain they said they will replace it because it was reported immediately with delivery personnel which I find it weird as why left it if they saw that its damaged but never did. Month later I reminded them about replacement they said the manager that was there is gone and there is complain written in computer and it's already late to replace it because they don't have it as other customers complain about and they do not have any in the ware house. I ask them to refund the money that was the last number they said my complain expired. Fine I called their head office and they said they will investigate and return to me which they never did on top of showed evidence. I don't know where to go I'm stuck with it