If the sim hasn't been used for over a year then the number is probably lost for good. You can get a new number by dropping into a Vodafone store when you arrive. Otherwise if it's less then a year mods can check the number/account for you on Monday when they are back and they may be able to reactivate it.
Cookie Vodafone Community Expert (or so I'm told) and S10 owner. I don't work for Vodafone