Someone stole my business idea,what should I do?

[Djorn]

I work at a school but I use to attend this university and hear people complain about the cost of ink there so when i left i decided to offer ink refill service once a week in the evening after i leave work but i was too tired to do it on the spot so the customers would have to wait until like the other week when i showed up. anyway i had monopoly and i was still making alot of money that way as they had no other source and were too busy to leave the campus. A month after i started i got really sick to the point i was in bed couldn't move, flu like symptoms and had to take sick leave. the day before i got sick i went shopping to buy expensive but good quality stuff like different inks and drills for my business because it was growing. I was so excited!!!! During the first week i was sick, the phone wouldn't stop ringing but my swollen tonsils and ill state did not allow me to speak with customers. when i recovered i hired someone who could offer the service everyday at the spot i used to do it. They could drop off the cartridge and get it back next day. I e-mailed all the persons who needed ink when i was sick and no one responded. It was like i didn't exist anymore. I thought maybe the girl i hired didn't have customer service skills for the week she was there until she told me when she collected her first and last paycheck that someone stole my idea.Someone is sitting very close to the spot i used to sit and offering the same service. They started and became popular for the two weeks i was away and very ill!!!. Not one ink for the entire week!!! so what do i do now??