Aircel
Deduction of balance

My mobile no. is 9501194333 of AIRCEL

i have a working BIS (blackberry internet services) over this no.

now the aircel is deducting my balance now and then by sending me the message cost: xxx rs. and data usage: xxx kbs.

i dont know wht they are deducting balance on there own and even when i am just USING THE COSTLIEST PLAN of the BIS..

everytime i get my phone recharged, after sometime they start deducting my balance...

and MOREOVER when there is ZERO bal. in my account they send messages for cost: 0 rs. and data usage: xxx kbs.