Hi jordanameliacarroll,
I'm sorry for any stress this issue may have caused you. It's most likely that the amount requested is an amount that was becoming due when your Self Assessment record was closed, and our system may have missed in cancelling.
To review this for you, you can contact us by webchat via
Self Assessment: general enquiries - just click 'ask HMRC online' and ask to speak to an advisor.
If you would like to make a complaint about your experience, search for:
Complain about HMRC
Thank you.