Vodacom Lack of communication to Customers

I had a sim card which we purchased from Vodacom which we have used for many years. I purchased R249.00 of data bundle 2gb last night, only to find out that it would not activate. I visited Vodacom Sunridge Park in Port Elizabeth this morning and was told that if we had not used it for the last 3 months the number has been given to someone else who now has the data. REALLY!!!!!! And the person serving us had an attitude of "Toughies that is the way it is." This is really not on as we have never ever been informed that if we do not use a sim card within a period of 3 months we will lose the number and it will be allocated to someone else. this is really not acceptable and we have lost R249. We tried to reverse the payment but was not allowed.