They should accept the old passport with the deed poll. I changed my name and gender and there is a lock on my account because of the previous "sensitive information" and it makes everything so much harder to do. Anyone with a lock on their account gets dealt with by a special office. The people on the regular phoneline have to be higher up and have to get permission to access the files. That's probably why they weren't able to access the information. Not sure why the national insurance number wasn't recognised because they can still access that and some basic details but not much else.
J - 28,student,married to the lovely Em and live with 2 cats Bilbo and Pippin. Diagnosed with Aspergers, Dyspraxia, Dyslexia, EDS-HM, Mild Asthma, Chronic Pain, Chronic Fatigue, POTS, Syncope