I.C. System, Inc. Debt Collection Complaint

I.C. System, Inc. Debt collection department,

I do not know Communication tactics Frequent or repeated calls Virginia

I received a call from I.C Systems. They asked me to verify who I was and I would n't do it. They asked to verify my address and I would n't do it but then I asked them why were they calling, but yet they would n't say why until I told them who I was and verified my address. After I would n't do that, the guy got really nasty with me and I hung up the phone and then blocked their number on my cell. However, they still call my cell house phone that I do not answer. Every time some one calls from I.C Systems, they refuse to tell me why they are calling until I verify who I am, but I refuse to verify anything because they wo n't tell me who they are.