Vodaphone incorrectly activating plan

Location/place: Mumbai

Name of company/service: Self

Dear Sir / Madam

I am Vodaphone use having below details.
Name:Jayprakash dubey

I went to Vodaphone office and their Customer Support Executive commited to renew my plan with 100 minutes STD free.
I confirmed from them 100 times that 100 minutes std free.But from last 2 months I found hat they are giving me 100 minutes local free.When I talked to them they explained that 100 mins local is free.

When they confirmed me that 100 mins STD is free.Why they have made such mistakes.

Now I told that I will not pay bill , unless U commit your mistake and return my money illegally taken by me

Kindly suggest how to proceed on that?

Thanks & Regards
Jayprakash