FAILED REFUND

I MADE AN ORDER ON DECEMBER 2020 AND MY ORDER WAS CANCELLED, WAS TOLD TO SEND MY BANKING DETAIL TO GET MY REFUND, AND IT IS NOW MARCH 2021 AND I STILL HAVE NOT RECEIVED MY REFUND AND I HAVE SENT THEM MY BANKING DETAIL 3 TIMES ALREADY. I WAS EVEN SO LENIENT WITH THEM THAT I PROPOSED THEY GIVE ME MY REFUND IN A FORM OF A GIFT VOUCHER, BUT THEY STILL FAILED TO ASSIST ME