OFFERS SETTLEMENT DISCOUNT BUT REPORTED TO ATTORNEYS AFTER

I was offered a discount via sms to settle my FASTA loan. I paid up less the 20% discount. This was paid up in March. But I got a call in June from attorneys to say I have an amount of R342 outstanding. I was told I need to call in an accept the offer before paying, however this was not stated on the sms. A Fasta consultant called me a while after and i confirmed settling the account on discounted amount. THIS is UNACCEPTABLE. I have been emailing LGR inc informing them that i settle the account after being offered the discount. But now I've been told that's not enough, I need to pay the R342.