Student Loan Company Will Not Accept My Details As Correct

Q*bert

As title... Student Loans Company sent letter asking to phone for refund.

Phoned number on letter and .gov website  and gave my usual details,

Stated my name, DOB and address and NI number. Was told did not pass security and because of data protection was also told, cannot tell you what was incorrect.

Phoned number again and gave details, name, DOB and address and NI number and was told they are correct and then the SLC Advisor changed his mind telling me they are not correct. I contended, "The details on the letter are the same as the details you were given and you are now telling me they are incorrect and the he admitted he made a mistake. I then asked him you told me the details are correct and now the details are incorrect - How did this happen.

He quoted data protection and is asking for a letter to be sent, along with a copy of a birth certificate/ licence to the SLC address...??

I then stated, the details you will receive will not be any different from the details given during the phone call and are the same details on the letter and you are asking me for now a copy of my driving licence/passport when you agreed the details given originally are correct.