I find that Audible is quite rude in one respect when cancelling a subscription. The way an Audible subscription works is that when you're subscribed, you get 1 credit for a free audiobook every month. If you don't use it, you keep accumulating them. If you have a few months where you don't buy anything, you can accumulate a lot of credits. But if you cancel your subscription, you lose all your credits, which you paid for! Yes, you can spend all your credits before cancelling, but I don't know right now which 5 audiobooks I want to buy, and I don't want to waste them on things I won't download, so I don't cancel right now.
You also have the option to pause your subscription. I use it whenever I’m accumulating too many credits, to catch up on my listening. If you didn’t like a title you can refund it after the pause.