Refunds are a mess

Never had a problem until I had to return a broken vacuum , had a handheld vacuum for a week used it once and it broke took the box it came in in the original takeallot box and brought it back to the pickup point I bought it from , it's been 3 weeks now and still no refund , they want a missing part . I've tried calling and emailing there customer support and every 4th day I get a different person to explain the whole situation with and then wait another 4 days until I have to explain it again . Please can this be streamlined ( we do not have the missing part as it was never delivered originally , I just want my refund now )