Good morning everyone. I bought an Iphone in January 2014 when I was in exchange in Canada, and the phone was unlocked. I passed sixteen months there using a Koodo prepaid chip and everything went well. But now that I am back to Brazil, as I try to insert a chip from my carrier here, the phone doesn't accept it and the only way to pass the "error menu" is to remove the chip. Then, I am unable to use my phone anyways. What should I do to fix this problem? Since I paid the full price for the phone when I bought it, this shouldn't be happening. Am I right? Thank you, Matheus.