bad laptop sold to me.

Location/place: kolkata

Name of company/service: Lenovo and dealer Eastern Logica

I had purchased a Lenovo Thinkpad 3245- AMB=1 for Rs. 39029.55 from Eastern Logica Infoway Ltd in Kolkata. The said purchase was made on 12th July 2013.
After purchase, I discovered that the laptop already had OS loaded by someone else. Not only that the language defaulted to Gujarati as someone had set that. It is a clear indication that the laptop was used by someone else. Someone had also created a OS media from the laptop and it did not allow me to do the same. The laptop was very slow to run. I could not use it properly. I informed the dealer about this problem on 6th of July 2013.

I returned the laptop to the dealer on 16th August, 2013. For no fault of mime, I am without a laptop. I will make a complaint online with the concerned consumer forum and proceed legally against lenovo and the dealer. I will also post the matter on social media and forums. I will take every step to bad mouth lenovo because of the treatment done to me. Further details of the matter are mentioned below.
The dealer’s service department told me that the laptop needed to be replaced. However, the dealer refused to take it back. Mr. Shambhu at the dealer’s shop introduced me to a visiting Lenovo technician. The lenovo technician said that by error a wrong OS had been loaded on my laptop. I wanted to return the laptop but they told me the OS would be reloaded for me. The laptop was taken by them and sent to your service centre.
I was told I would be informed the next day about the status of my laptop. However, no one called me. Today I called the service centre after getting their phone number from Mr. Shambhu at the dealers shop. I spoke to Mr. Pritam at your service centre. He tried to load Windows 7, 64 bit for me. However, when I called him again he said there was a technical problem which prevented online install of OS at the service centre. He said he needs to order a new media from Bangalore. I have been asked to wait further.
I feel cheated by the dealer and lenovo. How could I have been sold a laptop whose OS was preloaded by someone and recovery media already created? This is a clear instance of being sold a used laptop.
I want to get the laptop replaced and get a new one today.
I request you to please replace my laptop ASAP.