where can i change my iphone. it has guaranty

i bought two iPhones (6 plus) from Azerbaijan in Baku and both of them have a problem. at the moment i am in Iran. one of them problems is blue screen. my cellphone has a guaranty.is it possible to change it in Dubai?

and another one doesn't come up program. it has hacked by one person or one group. it needs one code to open. when i reset my apple id,s password. i don't have any email in my email address.

does apple agency give me a new iphone.