DOUBLE BANK TRANSACTION AND AFTER 3 WEEKS NO REFUND IN SIGHT

My vehicle was serviced at Motus Huyndai Menlyn on 14 May 2023. Wendy the lady at the service desk told me that my card transaction did not go through and I swiped for a second time. The next day they phoned me to confirm that they deducted the same amount double from my account. Very impressive up to here but then it went downhill. I went in personally to complete the form for the refund. provide my bankstatement, bank detail and copy of my id. Wendy keeps on assuring me that I will get my refund but it is now the 1st of June and still no sign of a refund. Not a email, sms or reference nr to confirm that I will actually get my refund. Yesterday I logged a complaint on the website chat and they assured me someone will send confirmation....... up to no NOTHING.. I will NEVER service my vehicle at Menlyn Motus again. Lets hope they will at last now react and pay my refund!!!!!!! No email adress on their website to begin with