Finally! Changed my number from VODAFONE to AIRTEL.
VODAFONE is one of the worst service providers have ever seen and the customer support representatives are irresponsible.
I have raised a complaint against network issue in HAL 2nd stage, Indiranagar, Bangalore in May 2013 and the issue is not yet resolved. The only reply from support team is " We are looking at the issue and we need to install network boosters" and they never installed it.
Me and my colleagues(more than 15 employees) applied for MNP from VODAFONE to AIRTEL last week because of this issue.