Nokia 5220 (Express Music) Mobile — mobile always hangs

hi
i purchased nokia 5220 express music handset in november 2008 from reputed mobile store kolkata ,but soon after purchase it kept on hanging always.i was out of kolkata after purchase to a remote area where servicing was not possible.i faced lot of problem.after few months i came jamshedpur where one day it finally got switched off.i went to nokia care where they kept the set for software upload.it nwas ok for 2 months after that and once again same thing happened its still with nokia care.are these expensive handset given to be always repaired till waranty and after that expense ur own or change the set.nokia was a name of most trusted mobile till i had purchased this.there is some manufacturing problem and they may be hiding it by saying it is because of internet and bluetooth use.it can be but it should be to that set also from where the contents r transfered.and if it is so why company provides data cable and blue tooth facility.i have however used bluetooth but never usb,still it happened.
smita