remove iphone data plan

hi i just want 2 ask that can i remove
my iphone data plan 'cuz most of the
time i use wi-fi connection.
other than that

its hard here to use edge 'cuz its to slow
specially between 11 p.m. to 2 a.m
im so disappointed about this on at@t
so i want to remove it 'cuz to cost me
$20 in useless service