I had problems with my check when I was changing it, because I signed in the wrong place of the check and because of it I can't receive the money

What check are you referring to?  And what does this have to do with your tax refund?

I'm Brazilian and this check is about my taxes of December that I worked in USA. I'm in Brazil now and I received the check and I went to an exchange house to change the check for money but when I had to sign I signed in the wrong place of the check and  they didn't accepted and told me to ask for another one

You need to contact the IRS directly for how to proceed in getting another refund check issued.

International Services 

If you are a taxpayer with specific individual or business account questions you should contact the International Taxpayer Service Call Center by phone or fax. The International Call Center is operational Monday through Friday, from 6:00 a.m. to 11:00 p.m. (Eastern Time):
Tel: 267-941-1000 (not toll-free)
Fax: 267-941-1055