Lewis Vryheid

I bought a bed from Lewis Vryheid late last year on account early this year I began having problem with bed sagging went back to store and logged a complaint the rep came and had a look at bed and agreed bed has to be replaced that was 3 months back the manager of Lewis Vryheid showed me a picture of another bed and we agreed on the bed she gave me a date 2020/10/15 that I will be receiving my new bed but it didn't happen she then gave me a date 05 November but still didn't happen I phoned their head office several times and the only response I receive is we will come back to you but it doesn't happen WHAT can I do