Deleted Vodacom number

My Vodacom number just stopped working, when I went to the Vodacom store I was told the number is deleted because its been inactive which I don't understand because I'm getting calls on this number everyday. Yes I'm not using it more often to make calls because I have another number which is on contract and I use it to call because it always have airtime. This Vodacom number which is now deleted I am using it everywhere, my accounts, my insurances, banking, etc. I was not even made aware that the number will be deleted and what I need to do to prevent that. How can I just loose an number that I have been using for years.