ALL minutes,data,sms GONE

So my vodacom contract expired and did not renew it, i put in a cancellation request and requested that the number get converted to prepaid once the contract is over as i would like to keep the number. to my surprise contract ended number was converted to prepaid but all my minutes,data,sms's THAT I PAID FOR was not carried over to the prepaid convert. i did the exact same with telkom and all my data , minutes was carried over when the number was converted to prepaid.

Vodacom come balance me quickly why was my minutes,data,sms's not carried over to the prepaid.