CreditOneBank Won't act on written correspondence Las Vegas, Nevada

3 months ago when I received my account statement there were several charges to my account that were not made by me.  Only one charge on the statement was valid.  I immediately contacted them by phone on a Saturday to inform them about the situation and followed up on Monday with a letter.  The situation appeared to be a security breach on their part.

They issued a new card a few days later and then two days after I received the new card I received a post card informing me about a change in address.  I tried contacting them again by phone per the instructions on the post card and all it would do was activate the new account.  I followed this up with another letter.

I received a statement last month with additional charges to this new account that I have been writing to them about.  In my letters, I have told them that the charges are fraudulent and that I do not owe them and am not going to pay them. 

They have not acknowledged receiving any letters from me.  But they call my cell phone and my home phone many times a day.  More than 10 times everyday.  When they call no one will speak, so I have quit answering the phone.  There is not e-mail address to send anything to.  And now if I try to call, all I get is an automated phone messaging system.