CAUTION!! Avante is NOTORIOUS for NOT being licensed & bonded to collect debts in various states. Before sending off your letter, be sure to check & see if they are in fact licensed & bonded (if your state requires that). If they are not, add that info to your letter. Add something like, "Despite that fact that you are not licensed or bonded to collect debts in (state), I am sending this letter to protect my rights. You have been reported to the Department of Commerce in (State)."
You can check if they are licensed by going to your state's Secretary of State website. Also, a quick google search will tell you if your state requires licensing. Hope this helps.