Product: Student loan

When I took my loan, I did not have a SSN ( because my green card was still in process ) and the lender company provided me with an Administrative ID to be used instead of a SSN. Now I have a propper SSN and I updated it with the said company. However, as can be expected, those two numbers ( the Administrative ID on the promissory note and my real SSN ) do not match. 

This is a problem because now I am trying to refinance the loan in question and the refinancing institution is asking me to provide them a document explaining the discrepancy between my so called " XXXX different '' SSNs. 

I have been trying to get such a document since the beginning of XXXX, but with no success. My first attempt was on XX/XX/2022. I requested a document stating that the number on my promissory note was an Administrative ID provided by the lender, and not my real SSN. The person on the live chat said she was having a manager looking into this type of request and asked me if she could call me later that day, because she was not sure how long the inquiry would take. I left her my phone nr and e-mail adress but nobody got back to me, even though she promissed she will make sure I was to receive a call by the end of that day. 

Not hearing from anyone for the next days either, On XX/XX/XXXX I called their customer service and made that request again. The agent told me it would take up to 15 business days. However, by the end of the said 15 days I only received a letter asking me to call them back. When I called, the person speaking to me seemed confused as to why I was asked to call back. After I asked about my request, he said they don't issue such letters or documents, and suggested that I have my refinancing institution contact them. This sounded very unprofessional to me because this is a very unusual practice and they shouldn't discuss my private information with third parties. Even if they were to be allowed to disclose such information, why wouldn't they just write that explanatory letter to me? Why put me off again? 

Later, without receiving any letter explainig that the number on my promissory note is an Administrative ID provided by the lender and not my SSN, I updated my real SSN with them. When I asked how long this process will take, I was told 5 business days. After 5 business days have passed, I called again to ask about the status of the process. The lady on the phone said it actually takes up to 7 business days. When I called after the 7 business days, on XX/XX/XXXX, this time I was told it takes up to 10 business days. When I told them that this was a rude way to treat a customer and that I was thinking of writing a complaint, they finally updated my SSN the same very day, on XX/XX/XXXX. 

However, when I made another request for a letter or document stating ( this time ) that they updated my so called " SSN '' from the promissory note with my real SSN, I was told once again that they do not issue such letters because they " do not have a format for it '' and they " have never done this before. '' I have honestly been very nice and patient with them, but it's been a month since I've been trying to get a simple document and I don't have much time left on my refinancing offer. I believe it is my right as a customer to receive some sort of document explainig why the number on my promissory note does not match my real SSN. 

The lender ( Sallie Mae ) specifically says in its online application that if a person does not have SSN then they can provided him/her with an Administrative ID instead. Moreover, when you call the lender, they identify you by your SSN, account nr, or Administrative ID. As such, I really don't understand why they refuse to help me and provide me with a letter explainig the discrepancy in my SSNs. 

My only guess is that they are stalling my refinance process in an attempt to gain more money from me and this seems like a very bad practice. 

I count on your help and would be extremely grateful for it! 

Thank you very much for your time.