Changing my last name with immigration

[kami_c]

Hi there,

I need some help on how to change my name with immigration.
My process was marriage based.

On 09.30.2011 - We got married

On 12.08.2011 - The USCIS received my applications: I-485, I-130, I-765 with also form I-864 (Affidavit of Support) and the medical exams sealed required I-693

On 02.10.2012 - I did the Finger Prints

On 03.20.2012 - Got my Work Permit

On 05.02.2012 - We went for the G.C. Interview and I got approved

On 05.10.2012 - My Green Card arrived

On 05.22.2012 - Requested my Social Security and it arrived on 05.29.2012

Now... when I got married, the lady at the court house told me I should write my name as it shows on my Brazilian passport, and I told her I wanted to change my last name to my husband's last name, and she told me I would only be able to do that with the Social Security administration.

So pretty much I went through my entire process, which I filled up also with my "original birth name", got all my documents and finally last week I was at the Social Security office thinking they would finally change my name legally once I presented my marriage license and green card and they refused it.

They said I had to change my name with immigration first.

So now, I don't know what to do. I have researched around and called the USCIS 1-800 number, apparently I have to fill up form I-90, which will cost me $450 total.

Is that right? and if so, will my marriage license & certificate be enough proof for them to send me a new Green Card with the name I wish to use?
I'm just afraid to send this and they deny it saying that I should have filled since the beginning with the name I wanted to use after getting married.

I appreciate any help I can get.

Thank you.