Please follow the following steps in order to overcome your current problem. I guarantee you that this would work and all would agree with it!

Step 1: Disconnect the line if its still active

Step 2: Pay the dues (you like it or not, its your responsibility)

Step 3: Try and sqeeze this money out from those who used the phone line (Which I doubt you would receive)

Step 4: In future, when you leave your current apartment make sure to disconnect/discontinue all bills under your name

Step 5: You will not post this kind of questions on QL (Joking)

Overall, you did a mistake and you pay for it.