9800 torch wont turn on ?

i had notification to update my torch so i did through 3g it sed about no phone calls for 2hours so i pressed install now now it wont turn on the loading bar will cme on then it will cut out half way through then flash white then restart again n keeps doin it its happened now 4 last 2days ive downloaded desktop manager but wont do anything cuz phone wont turn on plzzzz helppp thanks