This is a hack exploiting MTS MBlaze data card services for free Internet beyond the recharge validity period. It does not include a datacard firmware change and there is a very good chance it might not work for you. Seemingly, it depends on the network setup at different locations and so, it may work for some, but not for all.
There are two methods in this hack and both of these appear as I have heard of them from people. If they do not work, do not ask me in comments because I have never tried them myself. This is an exploit MTS might need fixing in some of its networks.
Hack MTS MBlaze Data Card Services for Unlimited Internet: Method 1
keep track of when your validity is going to end and start a torrent download at those last few hours. You might just be able to use your MTS Internet for another day if you are lucky. If you are on a prepaid plan, be assured that you will not have to pay anything for this extra usage. Enjoy thins cool hack.
MTS MBlaze Hack for Unlimited Internet: Method 2
Even after your validity is over, try reconnecting a dozen times. You will be connected at times and you might barely be able to push some HTTP requests (get to open the Google homepage maybe). This is your chance. Start a torrent download, see it catch up some speed and then it dies after a few hours.
This moment of joy can end anytime, so the legit way is to pay for unlimited MTS usage and not go rouge.