Service provider not being honest

I made an enquiry to the service provide about the interested items whereby I purchased a three-quarter dual function bed with its convector and the mattress of the bed. I also paid for delivery as per an indication of the where I am residing. They further that the turnaround time for the delivery is 2-3 week which they gave me 22 Nov 2024. I make a deposit cash of R7050.00 with a trust to wait and receive the items. 3 days prior the delivery date, the service provider told me they cannot deliver because there are no deliveries of the side I am residing which it was not how it was committed initially. I indicated my disappointment through their chat channel which they said that I need to pay R 1200.00 for the delivery to be done. I indicated that I have already paid R800 whereby I will pay the difference of R 400. I have never got a response from the service provider till to date. I tried to do follow-up last week and this week.