Double deduction for Petrol at filling station and treated like a *****

I purchased petrol on thr 1st of June 2019, with a debit card at the above dealer. Unbeknown to me (at the time) the attendant most probably swiped the card twice and two amounts of R500 each was deducted from my bank account. I was blissfully unaware of this as I only rcvd One sms on my cellphone, at the time. Later during the month, on the 22nd of June I was perusing my statement and discovered this double deduction. I duly went to query this with the bank and who confirmed that two transactions were paid for by the bank into the Engen Parow (Sonnendal)account. They requested me to query it further with the Engen Dealership. At the dealership on Sunday 23rd I spoke to Clinton (Supervisor on Duty) who said that he would hand the photocopy of the statement and my contact details to the relevant Manager who would probably refund me by the latest, Tuesday 25th June. I heard nothing from them and on the Tue 25th then went back and spoke to the Manager, Mr Steyn. He at first knew "absolutely nothing" about it and assured me he would inform Badroniesa, the accountant about it. Later he said that he "found" the bank statement on the office notice board. He also remarked that he could not consider this as important or Urgent, as U was asking about when I would receive feedback. Badroniesa also failed to contact me and I spent a huge amount of time telling her all of the above, on the phone. To date, nothing has been done despite me giving them the bank statement, which Badroniesa confirmed receiving, yet feels that this is not proof that I had paid for the fuel twice. This pathetic treatment of a client is absolutely unbelievable. I just cannot believe that despite being presented with irrefutable evidence I am treated with absolute suspicion and everyone I deal with seems to think that its just fine to treat a customer in this manner. I am totally "blown away" by their attitude.