can't access my 2020/21 self assessment

I have had an email saying it's time for me to submit my 2020/ 2021 tax returns when I go on to fill in my returns it's saying that it's complete, but I have not done them so how can it be saying already completed no tax to pay. can't email them to ask them to adjust it and reopen my portal so I can submit my returns by 31/01/2022 everytime I ring it cuts me off. any advise please?

Hi,
 

If your account is saying that the return is complete, you will need to check with our helpline. We are less busy if you are able to contact us before 10 am. See link: Self Assessment: general enquiries  . Thank you.