Differing settlement figures

I have emigrated out of South Africa and contacted Autopage to obtain a settlement figure for my account. Twice they came back with different figures (R7419 and R9043). Upon querying which was the correct figure, I was sent a settlement contract (i.e. a legal agreement) with a figure of R5631. Being an official document I duly signed this and transferred the money. They have now reverted and advised that the figure is in fact R9043. What happened to the R5631 and R7419? How can Autopage disregard their own legal document, the settlement contact, and now invent another figure? I have met their terms of paying, signing, and returning the signed agreement within 7 days. Someone needs to honour their agreement.