Viva Gym Fourways bad service

I have been trying to cancel my membership from Fourways gym on the website since last week. My 12 months contract came to end on the 24th and I knew I will not renew it. It kept giving an error and I could not physically go and sort this out. Now I managed to go today 26th and I am told I cannot cancel after the 25th yet I have a screenshot of an error saying I can’t cancel. Now if I couldn’t cancel before the 25th and even after the 25th what am I supposed to do. I will now be billed for a month that I won’t even gym for!!!