Thanks Mike and isabella, i m really conscious now, my twitter a/c has been hacked 2 times. Last time i had deleted my a/c but dunno why i re-opened. 1st time i unknowingly clicked a link which caused my a/c hacked but this time it was hacked automatically, dunno how. I seriously considering to close my twitter a/c now.
But thanks to twitter support who worked immediately n helped me, n they confirmed it was hacked.