Tax Refund on Stopping Employment

Please can someone advise on were I am going wrong. Ive been onto HMRV and they say my tax refund is circa £2200 for the following scenario… and I was expecting more like £4300? I earned £24385.55 in the first 3 months of the 24/25 tax year and paid £6485.00 in Tax. My allowance is £13830. I have now stopped work and will not work again this year. So my (rough) calculation that was backed up by online calculators but disputed by HMRC is 24385.55 - 13830.00 = 10555.55 So 20% tax should be around £2100? And therefore a refund of over £4300 should be due? The gentleman on the phone said hes performed the calculation twice and that I was incorrect in the above belief. Pleas can someone help?

Hi Paul,
Unfortunately, we are unable to provide specific advice tailored to individual circumstances on this forum.
This forum is for general queries only and is intended to help you self-serve.
If you have a question which relates to your personal tax situation you are able to contact HMRC:
Income Tax: general enquiries
On this page you will also see a link to:
Personal tax account: sign in or set up
Which may be the quickest way to review information relating to pay and tax history, tax codes and how to change them.
Alternatively, you may wish to engage the services of a professional advisor/accountant to assist with your enquiry.
Thank you.