I am a single parent that has been in my house for 7 years. The toilet has been running on its own for about 6 weeks and my water bill is crazy. A friend told me today that it might be the flapper in the toilet but that is not it because I had to replace this about 3 years ago and it is in good condition. What does look bad is the ball thing a majig, it is rusty and looks ancient. Without having to hire a plumber what should I do or replace? Thank you!