If the shit really did hit the fan, you'd probably be given an option by the bank to either pay it in full immediately, or they'd gain control of it. Regardless of what rate/period you both agreed on.
OP, just get the implant and be done with it. They'll get you eventually whether you like it or not. Just like they did the rest of us. We're programmed to disregard these kinds of posts so they only serve to expose the order's enemies. You can only elude the inevitable for so long.