Student loan payment overstated on tax calculation

My self assessment return is ready to file for 22-23 but it is stating that it is adding £2943 in student loan payments, at the year end my outstanding loan balance was only £814. I have tried calling the helpline repeatedly but I am unable to get through, is there a quick solution for me to amend this on my tax return? I am needing a quick resolution as require an SA302 for a mortgage, but didn't want to file and be forced to overpay then have to reclaim, Thanks in advance

Hi Michael Peters,
Once you submit the Self Assessment tax return the student loan company would advise HMRC of the correct balance and the calculation will be updated accordingly. 
Thank you