General :: Sony Xperia Z1 - Omitting Leading (0) Prefix From Dialer

I'm currently looking at rolling out Sony Xperia Z1s to our company users. At the minute, our global address list (in Active Directory/Exchange) contains all the phone numbers in the following format. +44 (0)1234 987654

When I select a contact from the global address list, calls and texts fail, as the recipient is resolved to +4401234987654. This is an invalid number

Connections to the global address list from iPhones, Nokia Win8s, and Blackberrys, that retrieve the same details, automatically omit the contents of the bracketed prefix and resolve to +441234987654.

We need to (ideally) keep the format of the contacts in the address list with the +44 (0)..... format, as these details are used to create email signatures, and with people based around the world, we need to keep the fully qualified international display format, also, I don't fancy the task of going through accounts of hundreds of people each with 4 different phone number entries, and editing them.