Vodafone India — wrongly charging me for service they did not provide

Address:

Kolkata, West Bengal, 7000068

Dear vodafone,

While my trip to the country of bhutan, i activated a pack of 149 under i-roam as that was the only pack available.
You assured me data and phone service but to my surprise there was no data service hence i had to purchase a local sim and used it on an alternate handset which supported my main handset through hotspot feature.

Yet to my surprise you have charged me a lumsum of 37 k against only data usage when all this usage was made through wifi as there was no data network on my handset.

Also when i have a credit limit of 13000 then how can you charge me so much money after my credit limit.

You are wrongly charging me any amount and this is not acceptable.
I have travellled to many countries but never such experience.

Ii want this seriously taken up