Pension withdrawal wrong tax code

I spoke to HMRC today regarding me owing 10k in underpaid tax after taking a few lump sums from pension fund. Apparently I was unaware pension company was paying BR code after I had claimed a refund on 1st withdrawal. No one told me rest should be at 40%. Now jobless and pot less. I owe this amount. HMRC said I should speak to pension company and pension company said I should speak to HMRC there fault Is it worth appealing this I obviously was to thick and uniformed that I had gone over an amount that requires more tax payable.

Hi Paul Dobbs,
We are only informed of lump sum payments after they have been taken, and do not usually have the opportunity to issue a tax code for this lump sum that's based on the rest of your income.
As such, the onus on ensuring the correct tax is paid on your lump sums is with yourself.
We may be able to help you pay the amount owed.
Please contact us by webchat or phone here:
Income Tax: general enquiries
And we can advise you further.
Thank you.