Golden rule = Never ever pay a collection agency.
That is, if you are sure that you owe some company money because collection agencies can also pester you about someone else’s debts or simply because their records are a mess.
Always pay the original creditor because if the collection agency messes up, and collection agencies often do, then you will be the one who ends up paying the price for their mistakes. You'll have no recourse.
(Unless there's a court order that instructs you to pay a collection agency if they've formally purchased the debt. It goes like this. You owe, say, 1000 bucks and they purchase it for say 300 or 600 bucks. The difference is the profit they make. The original creditor no longer deals with it.)
(Even in those cases, collection agencies can still play silly games by selling the debt back and forth between each other. When in doubt, do what the court told you to do, and ignore anything different that a collection agency tells you.)
I learned all this when I had a big tax debt after I'd gotten behind on filing my tax returns as a small business owner. I’d been too busy to get around to it, was exhausted due to sleep deprivation. Being in the middle of perimenopause may have played a role too, in hindsight.
(Bad excuses, granted, but I was keeping track, also of penalty deadlines, and I was going to get around to it soon. Then something very unexpected happened that put a big red cross through my good intentions.)
The collection agency clearly didn't have accurate information on how much I owed (and at one point even told me that I owed nothing). When I realized that, I informed them that I refused to pay them anything and would pay the original creditor. I did pay the tax authorities directly instead. One sum, in full, interest included. I had kept them informed of my intentions and how things were going and I sent them as much evidence as I could to support the truthfulness of my intentions. In the end, they were very happy.
One of the best decisions in my life. A rule I am going to stick with, no matter what country I am in or who exactly I am dealing with.
If you decide to do this too, straighten your spine and keep your feet firmly planted on the floor, no matter what people will throw at you, other than the original creditor, in most cases. Sometimes you may even have to ignore the original creditor too. Goal? Having firm evidence of what you paid and when, to the creditor.
It’s YOUR money. You decide who you pay it to.