Damaged goods

So I bought a jbl sub woofer from you guys on Saturday morning around 9 am . James was assisting me

On Monday I went to a fitting centre and was told the sub is damaged so today I went to autostyle for either a cash back or refund and was told I damaged it while fitting the sub woofer ( guy assisting me today is zubz) I cant believe this is the service I received as I spent 5k with u guys . Now I sit with a useless subwoofer and a lot of anger .