Poor service

I ordered an Infrared Thermometer on the 26th May 2020. Unfortunately,they couldn't trace my payment.Ive send proof of payment several times.Every time ,when can make a follow up I had to start afresh , though I quote the Reference number. I'Due to poor service I,be decided to request for a refund . Unfortunately I,ve send request several times but this process has become tirelessly withou at way forward..I need help in that regard, I want my refund