If you were married in the UK,
@Tony ********
you would have to get the marriage certificate certified back in the UK at Milton Keynes and the thai consulate in london, then have to get it registered at an amphur here so you could get the Kor Ror 22 form (thai married abroad).
BUT
don't let a lazy immigration officer dissuade you from getting the extension you want just because they wanna skate thru their job rather than actually do it 😛