Woolworths withdrawing discount offer when they caused a mess with the account

My Account was handed over about 1 year plus ago to collection agency due to me losing employment after covid. I have been making monthly payments to the collection agency. Mid Dec 2023 I received an discount on settlement of the account. I was busy getting funds together when on 17 Jan 2024 a new agency send me a sms advising my account is handed to the due to non payments (I HAVE BEEN PAYING EVERY MONTH). New agency advised discount no longer apply because account now with them. 25 Jan I received SMS that the SMS sent on 17 Jan 2023 was an error (SO MY ACCOUNT IS UP TO DATE) new agency sorry account now with us and you don't qualify for discount. Woolworths not prepared to listen to me and just refer me back to collection agency. Woolworths stuffed up here good and now I am being prejudice when I was about to pay settlement as per the amount they offered.