Loan Settlement

I have a capitec loan with Capitec that is at R283k now and it was handed over to Vertex solutions and i was called by Vertex asking me to write an amount i am willing to settle this loan for and i gave them a figure of R150k but i was informed that Capitec will settle for R174k and i paid the amount after i stated the reasons as to where i got the money, Why i came to that figure etc. and now that i paid off the R174k as agreed upon with Vertex, they came back with email stating that Capitec refuses to accept the cash and they can now only offer me the 30% & vertex wants to refund me and i will not accept the refund and i want this loan settled and updated on my credit record as being paid in full. There is no further amount of cash that Capitec and vertex will receive from me. Capitec must sort out this mess as i am being taken for a ride and this is not acceptable