I haven't heard of this but I'm not an AC guy. FYI, the most common failure is the valve inside compressor, it replaces the AC clutch function. Any place that does AC can do this service. Don't try to DIY since you have to pull a vac to refill.
And yes it's very suspicious that the AC was working when you brought it in. Tell the dealer to pull the codes as a courtesy seeing how you just spent $$$ and see what the codes are.