Losing power hour

Today I recharged and bought a power hour bundle. I got a surprise SMS giving me R100 vc tot vc calls. But now I lose my power hour, as the R100 gets used first at R2 per minute. Which is only 50 minutes in any case. At the end of the day it is not really a gift anymore. I demand my power hour that I legally purchased back. A special is supposed to benefit the client. And why am I barred from airtime advance seeing as I am a loyal Vodacom customer?????