Looking around I also see this:
https://www.trustpilot.com/review/playster.com
You can compare that to Audible on the same site:
https://www.trustpilot.com/review/www.audible.com
On first glance, both have similar ranking at 20-something percent 1-star reviews. But then I see that Playster has over 250 reviews while Audible has only 23 total, which strikes me as suspicious because Audible is by far the more well-known site. My first thought, egged on by my ever-growing opinion that Playster seems shady, is that perhaps Playster has 'stuffed the ballot box' so to speak to try to make up for the bad reviews.
Anyway, the 1-star reviews of them (close to 60 I think it would be compared to around 6 for Audible) mention things like sleazy advertising, bait and switch, misleading, false advertising, etc. In particular I notice many reviews say they advertise having certain books/audiobooks but once you sign up they don't.