Can company send me a legal notice if I don't pay the service agreement breach amount.

Hi, I wanted to know that can a company file a case or send me a legal notice if don't pay the service agreement breach amount. I was working for a company they hired us via college placement. The offered us a different post. In the starting of the training they forced us to sign a service agreement where we have to serve company for atleast 6 months on breach we have to pay 15000rs. We did it but after the two months when deployment time came they started to give the different position. We said this is wrong we don't want it. None of them were replying. They made people to accept that service desk position and they told us to give the position of dcop analyst (network analyst domain). We have already filled that service agreement and the time was passing. Since we already signed that service agreement and time was passing we accepted that service desk job. After doing it we felt it's like hell for us because of poor management and also it's not the job we wanted. We left after two months. Not only me there are 100's of candidates who left due to this. I know some of them very closely because they are my classmates. Now they are saying we will send you the legal notice. I have received a mail from their legal department saying this. What should i do? Even they are not sending it to everyone who left just some of them. They did fraud with us that's why no one has given penalty to them.