North American Bancard collecting money for service not provided detriot, Michigan

I signed a contract in 2007 which was supposed to save money!!! Within 1 week these people proved beyond any doubt that they will not be an asset to my company and I cancelled the contract in writing, by fax, by phone and in person with the person that I initially sined the contract with. They never installed any equiptment because I would not let them. We closed the business in December and in Oct I receied calls from a collection company collecting money for them - stating that I owe them $200 after they already collected $1200 for no services, no equiptment. they refused to talk to me. They never called me in person. They never returns calls. They should be prohibited from collecting money if they do not deliver services.