Hirsch's store credit

I bought a washing machine for Hirsch's in July 2020. In Jan 2021 i complained that the machine isn't working properly. After finally getting a technician out after months of back and forth, they now want to replace the machine. I said straight that I don't want another defy as the after sales service was not good. They said they will give me store credit for the machine as its been a year. I went to see what machines they have ans saw nothing that I wanted so asked if I can get my money back to go and look at another shop. They flatly refuse and say that I can buy anything with the credit. This does not sit well with me as I NEED a washing machine, the rest is luxury. I don't have R1400 to pay in for a washing machine that they want to sell to me. I saw one at another shop that I can afford