vodafone and blackberry — deduction of balance

respected sir/madam,
i am a vodafone user.i had activated my vodafone blackberry daily plan @15.
the vodafone website shows that we can use the service for using the blackberry app world.
i am a blackberry 9700 user.
i had activated my daily blackberry plan by sending the sms ACT BIS15 to 144 and Rs.15 had been deducted from my balance
and the blackberry internet services were activated in my phone.
my phone also showed the EDGE network and all my settings were fine for services to be used.
but when i used my blackberry app world,the vodafone carrier had charged me for that and deducted Rs.360 from my balance
my balance was Rs.322 and was brought down to Rs.-40.5.
i cant understand how the vodafone have charged me.
and also how can they make my balance negative to -40.5
i had not downloaded anything from the internet except just using blackberry app world apps.
this is malpractice and cheating from vodafone.
i had earlier also spoken to vodafone customer care but did not get a response.
it is my earnest request the you look into this matter and help me in getting my balance back which amounts to Rs.362 approximately.
i am looking forward for a quick response.
thanking you,
Dharmesh mahamwal,
[protected].