how to fix wifi on ios 7 not working

please confirm how to fix wifi conection on ios 7 because i try almost all the solution on the web and apple still not say anything please confirm somebody how to fix this because here in panama iphone is not sheap and this phone supoused to be the best but right now this because i have to used the data every time i even check my facebook so please confirm.

thanks

please help me im here in panama city panama and here an iphone cost 700 dollars yes american dollars not 100 or 50 so please help me helps us because im sure im not the only one with this problem

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