What are the Consumer Rights Laws in your country. You may know or may need to find out your rights.
In the UK the law is:
If a product is sold by misleading the customer, you return the product and you can get your money back. It is also against the law and you can prosecute if it has effected you (forced to pay postage) (Trading Standards) What Volkswagen did, loads of people are claiming compensation here.
If a product does not have an as expected or acceptable length of life (breaks 1 days after a years warranty) you can get a replacement, they pay for postage. They can argue it, but will likely give in. (Trading Standards)
If you warranty says if it breaks within a year we will replace it, they can then charge for postage and can repair or give you a re build one. (Depends on the warranty and laws in the country. Australia is really good for this.)
Your free to return the product within 28 days, for whatever reason. Provided its not been used, still in packaging etc. (But yours was sold misleadingly)
I don't know the laws in Brazil, you might be able to request your money back on the misleading part. But I think they will ask you to pay however much more the 290 costs, I don't think additional taxes are needed. So 280 is $300 including taxes, the 290 is $320, you should just pay $20 if you want that card. (prices just to prove a point). They sold you and maybe others and now want you to buy something more expensive + more.
I would ask/demand for my money back, from whoever sold it. Try to do it face to face or via the phone. Keep copies of emails and letters. They are in the wrong here. Does Brazil have any government body who deals with consumer problems?