Shocking after sale service

Ordered Armchair covers that were in a very shiny / slippery material which was not acceptable. I requested a return and full refund. They confirmed on the 11th of April that they would book the collection to process the return and refund. To this day, I am still waiting for them to collect and or advise when this collection is meant to happen. They have shocking mail etiquette and obviously have an internal issue for processing returns and refunds