216-766-5315

I get numerous calls from this number, but my caller ID typically will record only 000-000-0000? If I answer the phone, they say nothing? Is it allowable for a so called "company" to not show their phone number? I tried to call the number but it's either that the mailbox is full or it sounds as if the number is not working at all? I would think reputable companies would be required to transmit their phone number so that it shows on caller id I've noted them calling up to 10 times per day? I do not owe a debt, in fact the company owes me money. I think they call these types "bottom feeders"? How to resolve?