PnP FAILS TO DELIVER my order and then Refuses Refund?

I made the great mistake of placing an online order with PnP clothing in June and have had no communication or follow ups from them since (All communication has been strictly from me trying to find out what's going on).

I've made online support tickets, emailed and been calling their customer service for two weeks straight with no tangible result. I've cancelled the order and asked for a refund multiple times. This came to a head yesterday when their delivery service (after two botched delivery "attempts") sent me an SMS claiming delivery was made, - there was no delivery. After reporting this as **********, I'm still not getting any response or acknowledgment from PnP.

They failed to deliver and then refuse my refund and I've been dismissed the whole month (for something that should have taken not more than a week to solve)- I'm physically tired and don't know what to do anymore?