Renuka Enterprises — Bad behavior , bad service and fraud service

Address:

400101

I took airtel 4g wifi service from the above company
1. a wifi router of rs 3500/-
2. 10 gb data pack of rs 995/-
I was informed that this is the final payment and i wont be charged anything extra.
also after my usage is done i will get a refund of 50% of the router amount that is 1750 if i return my router.
now i got a bill of rs 782.76/- which the company says they are the taxes that i need to pay and refuse to take the router back and also give the refund.