Unknown balance deduction

Location/place: Gwalior

Name of company/service: Tata docomo

Hello sir,
I’m Prince Bansal having tata
docomo
mobile service with SIM no :
8871739865. On monday
around 10:35 pm without doing
anything i
got an message saying : You have purchased Trigonometry at Rs. 15 Click http://tom.tatadocomo.com/view,pack.phtml?id=361 to view the content of the pack. Non Renewable. Your Balance is 12.22(Rs) at 2012-11-19 22:20:49
: ……………
then i called to your customer care
executives
four time but each and
every time they say it isn’t our
mistake
…………i just
want my money refund back.