Standard bank not paying back my money

I reported a lost card whilst renting an Avis Vehicle, they debited R4 557.14 on the 7th of November and a week later came back to me and asked to make another payment for same amount because the transaction was reversed since the card was reported as lost. I made other payment arrangements. Till now I have not recieved the money back to my account. I spoke to their bank and they confirmed that the funds were sent back to Standard bank. Standard bank is not giving me any anwers I eventually had to fill a transaction dispute form and I'm being told this will only be finalised in January. This is totally unacceptable. It’s almost a month already and I can't continue waiting....I just want my money back. Avis provided me with proof that the funds were sent back to standard bank I don’t know why Standard bank is not paying back my funds.