Incorrect Employment information - Paying More Taxes than I should

Hello All, I've been facing an issue with my payments as it seems that one previous employer back in 2018 still sends information under my name/NI. In 2018, I've worked on a place for only a month then a move to another job. August 2023, I've started a new job, where since my first payment seems that I'm on the wrong tax code, affecting directly my net income. When checking my HMRC page, seems that my old employer, from 2018, started to issue payments under my name and for the HMRC seems that I have 2 jobs, with 2 incomes and that's not reflect the reality. When calling to HMRC, no one can help and states that I need to call my previous employer as their system still issues payments for me. When calling my previous employer they stated nothing was being issues under my name, but I showed them the statements from my HMRC and they start to dig on their end. They mentioned some error on the HMRC EBS system. They were able to contact the HMRC (on a second support level) but no progress so far. I wanted to check if there is any support line that could help me resolving this issue once and for all. End of this month will be the 8th payment that HMRC is collecting more tax from wages which doesn't reflect the reality as I only work in one job. Need assistance please.

Hi Marilia Tartaglia Marrara,
We are sorry you are having issues.
It would need to be our helpline that can check on this for you:
Income Tax: general enquiries
Thank you.