VERY DISAPPOINTED!!!

I bought my daughter 2 months ago the Vodaphone Smart mini. The price was reasonable and we were both very happy at first. We coudn't understand why her airtime disappeared all the time (in a matter of hours), unlike her previous phones. After visiting our local Vodacom branch, the asssitant helped us with a few settings and things were abit better until all her airtime vanished again that evening. One example....R29 airtime lasted a couple of hours!!!!!! We discovered that you can not have BBM on this phone??? Now she is sitting without a phone and i have waisted R549,00. I can not take the phone back as it doesnt have a factory fault & it's difficult to re-sell it as everyone has BBM today! I will not support Vodacom again as they shouldhv told me this before hand!!! Can anyone tell me what can i do now?