ECFMG Dean’s Letter rejected — need help from anyone who already went through this

Hi everyone, I need some help because I’m completely stuck with the Dean’s Letter requirement.

I recently graduated from medical school in Spain, and here the official diploma takes around 1 year to be issued after graduation. ECFMG says that in this situation it is possible to use the Dean’s Letter, so I requested one from my university exactly based on what ECFMG describes.

They issued an official document signed by the Dean confirming I completed the degree, that I’m a medical doctor, and I’m already working as a physician — but ECFMG rejected it saying it’s not acceptable as a “Dean’s Letter”.

My biggest problem now is that I don’t know what else to ask my university to do, because they believe they already provided what ECFMG is requesting. I’ve tried contacting ECFMG multiple times (emails, calls) but they are taking extremely long to answer and I still don’t know what exactly they want or what is missing.

For those who already went through this — what EXACT format/content does ECFMG actually expect? Is it supposed to be like the MSPE style used in US schools (with rotation evaluations, academic performance summary, etc.)?

If anyone has an example, template, or can explain what finally worked for you, it would help me a lot because this is holding up my certification and I need to schedule Step 1 as soon as possible.

Thank you so much.