Hi Morning Glory G,
You would need to contact HMRC to check what the issue is with the details submitted and to see if the marriage allowance transfer can be processed
Contact HMRC
To submit a complaint online you need to go to:-
Complain about HMRC.
Select complain online if you're an individual or a business or write the address is:-
PAYE & Self Assessment Complaints
HM Revenue & Customs
BX9 1AB
Thank you.