Pay OAT by credit card if you wish, but I think they charge about 3% interest on such payments. That's almost £2K extra on your costs to insure against losing it if (big if I think) OAT went bust mid-course.
OAT have been going bust for years (allegedly) if you search for it on these forums, but somehow they still seem to be in business and pulling in the punters, albeit a lot less than there was. Must just be a series of amazing escapes.
If you really want the answer to your question, write to OAT and press them for a written response.
As far as ganging up on them to force a change of heart, good luck. My course couldn't even persuade them to purchase videos made this side of the Black Death despite having stumped up £1million between us. (Remember my assault on the suggestion box guys? Funny how it disappeared after that eh?)