Can I change my master thesis topic and supervisor under following scenario?
Additional time is trivial compared to how you manage the relationships with faculty.
Ideally, you would go to your existing advisor, explain your dilemma/issue and he/she would be understanding and recommend that you pursue you new interest with faculty X.  That would allow you to maintain a positive relationship with the existing faculty advisor and avoid him/her communicating erroneously with other faculty.  This process is important to the extent that you wish to maintain a positive disposition of many faculty, not just him/her.  Will you need their recommendations any time in the future?
a
If you have an extremely tenuous relationship with your existing thesis advisor, xtent that you may need recommendations from any faculty for future employment, these steps are critical.  If you feel that your relationship with the existing advisor is weak, you might approach the department chairperson--but only if you are something more than a stranger to him/her.