Thanks Wyatt. It's really distasteful to have to expend so much effort to fix someone else's issues. Much appreciated.
No problem. It's the nature of this business. You'd be shocked how often we have to workaround odd network, driver, and kernel bugs (in all levels of the stack – and in all operating systems).
Thanks Wyatt, sorry for earlier outburst!
That's OK, I understand how frustrating it can be when things are broken.
What are the best alternatives now - any suggestions?
Honestly, Authorize.Net. It's a slightly higher learning curve, but you pay lower fees and they're responsive to problems. It's what we use.
Back when we started our business them and one other (now defunct) company were really the only games in town. And there was PayPal too, but that reeked of free-for-all-libertarianism that we didn't want to touch.
But, even give the many choices today, we'd still choose Authorize.Net for the control we have over it, and for the lower fees and higher reliability.