Vodafone India — unwanted ads before call

Address: Pune, Maharashtra, 411057

Each time i try calling any number i have to listen to a 10 to 20 sec ad about some service of vodafone...
Pls help me get rid of it... My vodafone no. is [protected]. It happens everyday.
Imagine a scenario, when I need to call someone urgently, and all I can do is wait for 20 second ad to be over before the phone at the other end rings.
I called the customer care center, they said "nothing can be done about it., contact the oburdsman".