I a bill in XXXX 2015 from XXXX XXXX XXXX about the " professional component '' of my emergency room visit to XXXX XXXX XXXX for the amount of {$620.00}. I called my insurance company ( XXXX XXXX ) and they said that it is covered by their XXXX XXXX and that I should not have received a bill. They sent XXXX a " Balance Bill Letter. " Later, on XXXX XXXX ( Dated XXXX XXXX 2015 ), I received a courtesy notification from Client Services Incorporated for the same bill that it will be going to collections in 30 days if I do not dispute it. I want to dispute it, but I do not know where to send the letter since there are XXXX addresses on the bill and do not specify where to send the letter of dispute. I am afraid to call them again because when I did they were very abrupt and kept changing the subject and asked me for my personal information like what is my previous address. They also said that it will go to collections on XXXX XXXX since they received it on XXXX XXXX. How do I keep this off of my credit report? I am willing to pay it if I know I will be reimbursed later but it is unclear if it 's XXXX XXXX 's or XXXX 's responsibility.