poor service

ive bought a base and mattress at kaysies on 20/4/2019.the salesman assured me the bed would be right for me. after a month the bed has a big hole in the middle and the whole mattress springs are clearly worn out. after i phoned and spoken to riedwan he said he has spoken to the factory and actually the bed are made for a kid with a weight of 40kgs. The bed are almost more than a meter high my question how on earth will a kid get on the bed and why didnt the salesman told me the bed werent right for my weight. Kaysies refuse to refund me or give another bed theyre explanation the salesman wanted to make a sale only thats why he didnt told me this