I am kat an international student, I had applied for a tier 4 for a course 4 months Pre master's course and received a tier 4 today for 4&1/2 months.
However, i wish to change my course and reapply for a different course at a different university at master's level for 1 year . i read i need to apply for new visa with new cas, however i am worried of the below and need URGENT help as i am constraint by time.
1) If i get a new CAS from my new sponsor and make a new tier 4 application for the same start date as in change my choice of course and university, will i get a new visa if the documents are correct ?
2) In case i get a new tier 4 visa granted, i know the old one will get cancelled.


I do not want to lose out on my existing course and visa if there is a possibility of the old one being cancelled!!
3) or is it that if the new one is rejected they cannot cancel the old one ??
i am unsure of the protocol of the ukvi and need urgent advice and help!!
please aid and maybe help me choose correctly and avoid confusion.