American marriage certificate for Residential Visa

Greetings!
My question for married couples who came to Bulgaria for retirement. How did you apply your marriage certificate to Immigration Service? They want us to apostle the document, to translate and legalize in Ministry of Foreign Affairs. At the end we have to give this original document to Immigration Service and.....practically lost it !!! When I refused to leave original document, I receive an option: to make a copy, translate, notarized. Sounds right. I went to Translation/Legalization office. Folks looked at   original marriage certificate and said : for Legalization you need an apostle. I explained that Immigration Service was agreed on translated and notarized copy. Since it is a  copy, Legalization is not needed. So we called to Immigration Service.  Immigration Service after question: Do you need legalization and apostle, says - Yes! They need apostle and legalization.
Same person in the same organization gave two different answers.
Does anybody knows the right answer?
Thank you for your help

I have never been able to use a US document in Bulgaria (except my passport) without it being apostilled and then legalized here. They have never accepted a copy of an apostilled document for my US documentation- it had to be an original. This wasn't specifically for a marriage certificate, but for the criminal background check and again for the high school or college diploma for getting a driver's license here.

I have also been told multiple things by multiple people- but I find it a waste of time to try the easiest way, because they never accept it.

Thank you kojidae! I sent a request to Secretary of State of Iowa (were we married ) that's was the advice on American Embassy site - Embassy does not apostle that kind of documents. Hope that will work.

EVERYTHING that we submitted to them had to be translated, notorized and for legal documents apostilled. It was an enormous pain in the butt. And I was giving them the originals!

Oops. Meant to say, that included our US marriage certificate.