United Consumers Inc Debt Collection Complaint

United Consumers Inc Debt collection department,

Medical Cont'd attempts collect debt not owed Debt was paid Maryland

My son has been constantly harassed by United Consumers , Inc. ( -, VA - ) even after I have sent them correspondence - with proof that the bill for emergency medical services has already been paid. United Consumers is making threats about effecting his credit rating and other forms of intimidation.I would appreciate it if this matter could be looked into. I have attached a copy of the cashed check, which was sent directly to the hospital. ( And cashed by them, as well. )