Buyer not accepting refund

Facts I, am a sole trader and sold an empty Dry shipping container bearing no 12345 on June 14, 2023 to the directors od a small company company. The money was paid in full by bank transfer. The container was due to be picked within 2 weeks by the directors . On June 26, 2023 I was informed by the shipping lines who had originally sold me the container that the container was inadvertently given to another shipper by them and they are ready to refund the cost of purchase or provide available replacements in same location. The same fact was communicated to the above directors on June 26, 2023. They neither agreed for replacement or full refund of money including GST. They are threatening to trap me in a false case of cheating by using their political connections, if I am not agree to their malicious demands. I understand they have already filed a complaint against me with the police I am not privy to the contents of the complaint filed by them. However, I would like to reiterate the following facts It was a simple trade deal between seller and buyer which was disputed and a refund of full money was offered by the seller, since the alternative replacements were rejected. The director have not provided me with the bank details or cancelled cheque for crediting the refund till date even after repeated requests since June 26, 2023.