LVNV Funding collection notice to elderly father

I recently was appointed attorney-in-fact (power-of-attorney) for my 85 year-old father and have full control/responsibility for handing his financial affairs. Before this all became official a week ago, I did some sleuthing to confirm suspensions he was not taking care of financial obligations (utilities * taxes. Thankfully mortgage paid on time!). In a pile of papers I came across a collection letter from a LVNV Funding stating amount owed and a settlement amount for Lowe's. Unfortunately, my father just a few days ago threw out all of those papers before I came back to the house. Having to go on memory I believe the notice was dated within the year. There was only that one letter that I could see from LVNV. I ran a credit report last night and sure enough LVNV Funding shows up on his report as collection with open date of 11/1/2006. I know for certain my father has never had an account with Lowe's. However, my stepmother may have but she died in 1994! Prior to her death she would have me help her write out her few monthly checks and I do not recall one for Lowe's. I believe my father when he says he never had an account with Lowe's and hasn't been in the store for years. I don't know how to proceed because I don't have the paperwork before me. Do I wait until another notice comes to the house and then send a "dispute" letter, including certified copy of the notarized copy of power-of-attorney? Do I go ahead and submit a dispute to the CRA?