Just found out that Presto has been charging me full fare for months when the account and the card details clearly show a concession. Just been on the phone for an hour, first because their website is buggy, wouldn't show my February transactions (problem is related to the drop down arrow top right, I suspect a Java issue, they agree, Firefox using customers been complaining a lot) (I use Chromium, so that's not it) but Presto's service reps don't help. First one (a "website specialist") actually understood my angst after my repeating it slowly three times, then she agreed. "I'll send a report to the back office"...OK. That was to fix the buggy on-screen java.
Hang up, then get website working properly, only to find the overcharging has been going on at least since January. History not available before then. I call back (and call time and again, since the menu is screwed up too) and ask about the overcharging. "Can't help you, not a Presto problem, I'll put you through to the TTC". It's a recorded message, no-one there. More wasted time. But it's not their problem! They only supply taps or not, not what the software charges.
Call back yet again, finally get someone who agrees it's their problem, and they're taking it very seriously. I'll also be getting the overcharge penalties I've been paying too. Not a lot of cash, but it's the principle of being fugged then spit on after.