I have exact same problem on same model of Fridge, in my case, I suspect it is because I didn't tilt the fridge backward a little bit, as when I roll out the fridge to clean the dust, I unscrew the legs in the front but when I move it back, I didn't screw it up again to make it tilt.... so the fridge leak the water on the front left side instead of at the back dripping pan....

so I just screw up and hopefully the problem resolved....

the guy who charge you $140 could have done that too.....because I don't think the drain hole can be plugged easily for this model.