Incorrect State Pension/Benefit as deduction on Personal Allowance

Hi. Would like to know if anyone else has had this issue. First thing to point out is that I have not yet reached the age for State Pension. Second thing, I am not receiving any taxable benefits. Yet, there is a deduction of >£10k on my Personal Allowance. I have spent hours on the phone to both HMRC and DWP. They blame each other. I raised a form on HMRC on-line that has been completed without resolution. I have sent a mail to DWP complaints a couple of weeks ago that has not even been acknowledged. At my wits end with this. I am owed around £5k in overpaid tax because of this. Grateful for any suggestions. 

Name removed admin .

Hi,

We are sorry you have not been able to resolve this issue. As we would need to access your record to review this, you will need to contact contact our Income Tax team.

Income Tax: general enquiries

Thank you.