Tax Relief on Personal Pension Contribution

I paid a lump sum contribution to my Teachers Pension fund - THIS WAS A POST TAX PAYMENT. The Teachers Pension fund have informed me that they have not claimed the basic tax relief on this payment. I am a basic tax payer. Can I claim the 20% tax relief on the payment and if not what happens to it?

Hi,
Yes. You will need to send in evidence of the payment to:
HMRC PAYE & Self Assessment
BX9 1AS
Thank you.