Bad Service and no refund for incorrect material

This Company and it's owner provided me with the worst service ever, firstly I had to wait 3 week after I paid for Roof sheets to be delivered, then when it finally arrive at 10 o'clock that night we realized he provide us with 0.2mm sheets and not the 0.4mm sheets we ordered and paid for. We have been at their premises have phoned then, emailed them and send them messages, it is now a month later and the owner has still not refunded us or tried to rectify his mistake.

The owner keeps promising and making excuses, guess we will never get a refund and to crown it all they had no Covid protocol in place in their factory.