Poor quality restonic bed

I purchased a restonic bed from OK furniture in March now the bad is already finished making noises they offered to replace the mattress of which I accepted now they want me to arrange the transport to collect my mattress and bring their mattress as if is my fault they sold me poor quality bed I paid for the transport to collect my bed after purchase I can't be paying for their poor quality materials issues they have to replace my mattress bring it and collect their mattress