Overall the years, I have acquired 24 audible credits when I was a "member". I spent 14 of those credits on titles in my library (other titles were purchased by other means). I recently purchased a title using a credit. I even listened to the first few chapters of it. Today when I tried to listen to it, it had been removed from my library. (It can be clearly seen in my listening history)
I called customer service expecting to have it restored. It was not. Nick tried to tell me that because I had canceled my membership, I could no long listen to titles that I purchased with credits acquired from that membership. Its bad enough that credits that I paid good money for seemed to have expired. But I didn't know that books purchased with credits would also expire. That really sucks! Its like they broke into my house and stole the book from me - even after I handed them over $100 for credits that they're not going to let me spend. Theft is a good business model, I guess, as long as you can get away with it.