Can't change Creative Cloud Pro plan

I signed up for a free trial for the Creative Cloud Pro plan (annual, paid monthly). I forgot to cancel my free trial so I just got charged $67.99. Now I want to change my plan into something cheaper but I couldn’t find any option for that, I can only cancel the plan but that will cost >$300. I tried reloading the page but it keeps saying that there is a Billing issue, after I try to ‘Retry the payment method’, they said that ‘Your payment method was updated, and we received the past due amount for your subscription.’ but after that when I reload the page, the ‘Billing issue’ appears again?

I don’t understand what is going on. Is it because I don’t have enough $67.99 on my card? If so, I have just paid $67.99 a few minutes ago for the first month so why would I need another $67.99?

Please help me out. I really cannot afford this, I need a cheaper plan or change into a cancellable plan. Thank you