That sucks. I vaguely recall this saga a few months ago. Just won't quit. Makes me nervous about my CVT... I'm thinking I'm going to trade out of it in a couple of years.
Not sure what is best here. Clearly the shop needs to make this right. Maybe replace the radiator too, as it probably has a cooling loop in it, and maybe they cannot flush it properly. AKA replace everything and hope the customer goes away--which at this point, is what I'd do, trade this off, as I'd be rather put out.
Then again, as we all know, for 1,000 remans that get sold, some percentage will fail early--and some percentage of those replacements will fail in short order too. Stats game here. But that's little consolation to whoever has to deal with the aftermath.
Of course, maybe this is ECU (TCU?) related? some sensor not read properly, or an ECU that is not quite right in its head.