Bonus airtime not allocated

I received an SMS this morning at 08:27 saying that I now have R300 bonus airtime to use until 23:59 tonight. I made 1 short call & noticed money was deducted from my prepaid airtime. I made a second call and after 2 minutes the call ended & my prepaid airtime balance was zero. I called customer care who firstly said the R300 bonus airtime was allocated for Data, secondly said that by 08:34 that bonus airtime was depleted (7 minutes after being allocated). She also said data costs R2 a minute, that's incorrect, it's R2 per MB - I know that & im not employed by vodacom. At 08:37 I was using wifi so there is no was the R300 could have been used for data. So what really happened vodacom? I would like my airtime refunded.