Airtel — cheated by big fat liars

Address:

North 24 Parganas, West Bengal

I took unlimited data plan from airtel. 699 for 2 gb . after which I will be charged 2p/100kb . After using 3.435 gb (Rs.1000) , it will become unlimited and speed will drop around 200kbps-1.1mbps. But I am getting no more than 20 kbps even after using it just for 2 days. Even after calling customer care 5 times and making a round of airtel shop in city center , salt lake , the problem still persists.
Something like this happened to me before with mts cdma connection . I was lied about the speed .
But this time I thought its AIRTEL , so I was confident.
Nevertheless,let down by such a huge company. May hell break loose on you guys.
I saw on my airtel that my charges till now is rs. 3200. How is it possible for an unlimited connection?