I'm Bill Harding, founder of Bonanzle and occasional supervillain. I'm sorry to hear that your Bonanzle experience wasn't what you'd hoped it would be. I presume the $25/month that you speak of was the monthly charge for a premiere membership that you had signed up for?
For the reference of future visitors, this membership can be canceled at any time, either through the link to your membership on Bonanzle (near the top of the "My Bonanzle" page), or directly, through your Paypal account.
It's difficult for us to modify Paypal subscriptions ourselves, because Paypal stores all of the subscription information on their system, and we don't have a direct mapping from that to our users. I suppose we could try to figure out a way to allow our support team to directly access Paypal accounts, but in the six months since we started offering memberships, only a couple sellers have been unable to find the link to unsubscribe. And now that we're offering memberships directly on site (as of a couple weeks ago), we'll have a much easier time canceling memberships via support requests, when our subscribers are unable to find the link themselves.
Still, as you mention, even for the couple people we've had who haven't managed to unsubscribe themselves for whatever reason, we've went ahead and refunded the month they hadn't intended to pay.
Hope this helps yourself & others to understand this situation better.