My previous employer has still reported earnings

I stopped working for my previous employer on the 28th August and received my last pay on the 5th September. However, they have reported to HmRC that they have still paid me on the 5th October which is incorrect and as i’m not working currently this has affected my universal credit and my HMRC information. I have messaged them but have not received a response either.

Hi,
Unfortunately, it is not possible to check individual tax records through this forum, if you have a question which relates to your personal tax situation or tax code please contact our Income Tax team:  
Income Tax: general enquiries
Thank you.