Intec college messes my financial life

I've deregistered to study with intec college for 2021 in may, but they took 2months to acknowledge my cancellation request, did follow-ups back and forth with no assistance. The recent response I got in Feb 2022 was that I owe them full tuition fees if I fail to provide evidence that I canceled within the "cooling-off" period(which I did in May 2021). I have a trail of emails from Feb. 2021 requesting access into their study portal and got assisted in May, follow-ups, call records and facebook complaints that were not attended to. Now my credit beurea is impacted and my job is in line because of this! No further assistance I ever got after providing my evidence. INTEC COLLEGE is misleading and messing up peoples lives!