Portfolio Recvoery Harrassing and will not give info on so called debt or mail us info on debt Norfolk, Virginia

They continuiously call and they are showing on credit report but when we ask them to mail us paperwork regarding the debt they refuse.  They could not even provide me with amount of debt or who the debt is to, after finally getting a mailing address from them cause I refused to give them any bank account numbers I googled them and read all sorts of negative reports and I am lucky I did not give them my banking info.  But I find it weird that they would not send me info on this account and they wont stop at no cost.  They claim the debt is for one company however my credit report says another and they claim they do not have to send me any info just take my account numbers.  I have dealt with collection agencies in the past and they have always sent me the info and willing to work with me.  How do I know I really owe this debt and what if its not really my debt...  They were extremley rude, and I wonder how they got my cell phone number beings my phone is under my girlfriends name.  And the company on my credit report, the original debt collector is no longer available to contact as it was western wireless and they were bought out by all tel whom now was bought by at&t.  So what do I do here.  I'm affraid to pay these folks or give account numbers as I have read peoples bank accounts have been drained and i sure do not need that happening to me, however its reporting on my credit and I am not sure its my debt, so at a lost how to resolve this issue