Vodafone India — default caller tune cancellation

I downloaded the vodafone caller tunes app from the play store and when i opened it a default caller tune started after i logged in and now i have been trying from several days but i am not being able to deactivate the default caller tune and every time i am trying every ussd codes it shows that deactivation is not allowed for corporate subscribers. What should i do now? I have even called the vodafone customer service but it is not working they promised to deactivate it but they fail to do so, the default caller tune is very annoying and at any cost i want to remove it. I have tried several ways but every time it fails. Please help me out regarding this as soon as possible.