no matter what i do, my apple id will not work on my iphone anymore i4s. but i can use it on a computer only. ???

no matter what i do this is not working.

on any computer i can log on to my apple.com web with my user name and password.

but....

on my iphone (i4s) no matter what i do.....it will NOT work. tells me the account is deactivated and no reason why?????

anyone know what to do????

i already shut off the phone, turned it back on, did a soft reset, nothing works.