Vodacom SIM card deleted - AGAIN!

I have a prepaid SIM card that I use infrequently. In order to keep it active, I use it at least once every 180 days, as previously instructed by Vodacom. I used it in January this year, and when I tried to use it now (still within the 180 days), it failed to register. The call centre agent told me it was deleted after 90 days of not being used. So that's a serious conflict of information given to me by Vodacom, and by deleting the number, they have also taken away from me the airtime balance of R500.93 that was on the card. I am asking for my number and the full airtime balance to be restored to me. Please assist. Thank you.