Not to be trusted

Purchased a JBL sb150 sound bar , the product was faulty from day 1 sub woofer would not power up , returned the unit after talking to the shop manager Patrick who said just bring the sub woofer in we will replace it , arrive at the shop to be told they need the complete unit it has serial numbers, after a long discussion they loaned me the sub woofer from their demo unit, and we agreed I would return the complete unit at a later date and it would be exchanged for a brand new unit, the new unit now has a problem and Patrick is refusing to replace the unit (be very careful when dealing with this man he is not a man of his word he does not return phone calls and changes his story) I have now made contact with JBL head office and surprise surprise they don't respond to emails.