Paid in Full and Job not done

Around September 2020 I made contact with WeQ4U and requested a number of things to be done, I received a quote for everything to be done and paid it in full. Halfway through the process I'm told to pay a further R2000 to complete the process that was originally quoted for and on the quote. I called them and wrote several emails but they just don't seem to understand that I've paid for everything and refuse to do anything without further payment. Just beware