Who is computech and what services are they rendering?

I have a problem with the company called computech. It has been sending me countless emails and messages claiming that I owe them. But to be honest I don't know them or what they deal with. I feel that they are harrasing me and I have asked them to send me information about what I owe and how, when and the services they have rendered to me but they have failed, all they do is is harass me with emails and messages that I owe them and I have to pay or else they will hand me in. When I try to call them the phone is not answered and my emails either.