@Marc, can understand your frustration but in my opinion Flynax is one of the best companies I've been working with when it comes to support. Sure it can take a while sometimes but they always respond, even same day in many cases.
What you ask about is for sure a modification that affects a great deal of the script which takes a while to insert and secure for bugs. As a user it seems that it is easy but for a programmer you have to think about the whole functionality.
There's a lot of information regarding the field for phone number in this forum and there's a lot of skilled people here to support you.
I'm sure Flynax will respond.

//Morgan