Vodafone Idea Ltd. — wrong charging for data usage

I had taken international roaming package for 30 days by paying rs. 5000/- for 30 days, wherein i was offered free unlimited voice incoming and outgoing calls anywhere in the world whilst travelling in canada and usa. Also free unlimited data usage whilst in usa, except some charge on data usage in canada.

I have been wrongly charged for data usage in usa, by vodafone idea ltd. Claiming that my number was latched to a non-partner service provider viz bermuda at & t, usa. It is a wrong claim made vodafone idea ltd. As i had set my hand set on mannual selection of network, hence there was no chance that my number would get latched to any network, other than i choose to connect.

I have complained to vodafone idea ltd., that why was i not alerted, immediately, when they got to know that my number is getting latched to a non-partner network, to which they take a stand that they would get the information only after 15 days.

My stand is that in their bill, for the period from 7th august to 6th sept. The data usage is recorded on 22nd & 23rd august, (Which is 16 days after they claim, of the usage of data on non-partner network), yet they did not alert me for the usage of data on non-partner network, before sending the bill, hence i have a doubt that i have been wrongly charged, for the usage, which i have not used.

Whilst i was in canada, i used to receive daily alerts, on the usage of data, hence i was able to know my daily usage, for which i have agreed to pay the charge as per the terms of international roaming package.

I have made the full payment of the disputed bill under protest.

I invite from readers, to suggest, to me, as to what should be my course of action.