oral intimation to employee transfer from one department to another is valid ?

oral intimation to employee transfer from one department to another is valid ? if valid and employee accept the same but later on informed to management that he/she not adjusted in new department and he/she want to leave job but demand 3 month salary. What action management will take against such employee ?

Interdepartmental transfers are always done by written communication to employee, old department and new department, finance section etc.
Oral instructions can create misunderstandings of this nature.
As far as exit is concerned, it depends on conditions laid down in appointment order.Employee needs to be informed accordingly and adviced on procedure to exit and also can discuss what is the problem with working in new department.

Hi Chbhagat,
Here you have to remember one thing, the Management has offered the work to employee be it in the old department where he/she had been engaged or a new department.
If the employee is not comfortable he/she has to speak to them professionally and get it resolved.
And if the employee is demanding notice pay,Management can ask him/her to continue during the period and give the required notice,look for replacements.
Management need not pay the notice period pay on this pretext.

Thank you very much Mr.Nathrao and Mr.Venkata Vamsi Krishna Patnaik for your reply. It's really helpful to me.