Bad sound fitments

I went in knowing exactly what I wanted. The technical team told me that the amplifier I wanted was to powerful for the subs I installed and gave me a smaller amplifier...two weeks late the amplifier malfunctioned. I took it in for repairs on the 6th of December 2022 and went back today to collect only to find it missing. No one knows where it is. When the owner found out about the consulting he said the amplifier was to small and was not the right fit. Yet he wants to give me a smaller amplifier for a retainer until they find mine...day light robbery...