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Sorry to hear that. I know how excited you were waiting for you tub to come in and now that major disappointment. I would not go with the option of changing sides on already installed tub. The less anyone touches the tub or works on it the better I think it would work and longer it will last.I would ask dealer for the order details as it got submitted to the factory and try to figure out where the problem happened. Was it the dealer who gave your tub away, or was it the order that was placed incorrectly. Depending on the outcome I would then contact the factory and made a big stink about the whole thing.
I would probably start calling Jacuzzi by now. If my day got ruined by dealer like that I would certainly give it my best to ruin it for the dealer as well.