Bad Customer Service

I received a post card form this business and I get one approximately every month from this business. I wish to be removed from their mailing list and usually I send a letter requesting to be removed. The mailing did not include a mailing address, so I called the number on the card. The person I talked to told me that I might get one more post card, but he did not make any effort to verify my name or mailing address where I was receiving the unwanted mail. I kept asking how he could remove me from his mailing list if he did not verify who I was. He did not answer this question and became very rude. He told me I was wasting his time and threatened to report me to the authorities. Strange behavior I think for a business selling quality answering services. On the second call he hung up without confirming that I would be removed from the mailing list.