refusal to deliver by teh service provider

I had agreed with Rebecca for her to do the decorating and catering for my wedding. My theme changed long my planning which changed the quote amount . I have already paid a R10 000 deposit for the original R47 000 quote. then she failed to satisfy my preferences when I went for the mock up. whatever additional ting I would ask that she adds she would say \I don't have it' . so I decided to go to another service provider. I asked her to use the R10 000 deposit I gave her for cooking labour as she had quoted R8 000. she refused and says she works according to the terms of her contract