Calculator [Q] Can you alter ROM / firmware on conventional phone (Gusto2)?

As the administrator of a group of prepaid users I have a need to alter / limit some features
on the Samsung Gusto2 U365.

#1 on my list is to re-route *611 / 611 calls to my office (or disable if that's not acheivable).

I'm ready to reward you fairly and wholeheartedly if you have experience doing things like this
and want to help me with my project.

Many thanks,