Taking money without delivery

On June 2020 I have got a tender from Department of water and sanitation for supply and delivery of 10 Units of Lyren B series G345SA hydraulic power units. I have searched and fined it at Company, Glen Burrows & Co in Cape town. The costs of them was R166 980,00. We did arrangement with them and finally we come to the conclusion of paying price for insurance cover of 30% (R50094,00)of the quoted price. But I didn’t understand the percentages so I calculated that 30% from R50094,00 and it has gave me R150029,00. I have deposited R150029,00 to their account and I have the proof of the money I deposited. So it was on Thursday 04 June 2020 when I deposited the money on their account and she said the money isn’t enough to cover the insurance but she had spoke to the manager and they will deliver it on Saturday. According to the department, those people didn’t delivered the units. I have send several emails and I call the Sales Executive of their company, when she hear that it’s me who is calling, she drop the call or its ringing until it’s go to voicemail.