Vodafone India — balance got deducted unfairly

Address:

Kolkata, West Bengal

I have recharged with rs 35 in my mobile and by mobile balance shows rs 55 on that day. After few days i saw my balance is only rs 8 left in my mobile. I have not taken any service. They have unfairly deducted my balance. Kindly please resolve the matter. I have also not made calls from that number. So why they have deducted my balance unnecessarily?
Please refund my amount back.