Perhaps this wil help others who have had the same problem.
Within 2 days of delivery, our new RS27T5200SR, which we'd set at 37F (fridge) and 0F(freezer) was freezing salad greens and cabbage in the vegetable drawer (2d one up from the bottom of the unit). We called Samsung for warranty service; the call was dispatched to Home Service Network, and a HSN-Samsung tech arrived within a day with a replacement part.
The story takes a darker turn there. First, no real diagnosis was performed by the tech, not even measuring the temperatures in either compartment. Second, the tech showed up with a part that wouldn't fit our refrigerator despite having the model and serial #. His efforts to do so resulted in the original part being broken, an apology, and "we'll be back soon" with another replacement part. We set the refrigerator temperature to 43F and crossed our fingers.
Visit #2, a week later, was shorter. Tech didn't even bring the new part into the house. Said upon examining it in our driveway that it wouldn't fit! "So sorry, see you soon".
Visit #3, another week past, resulted in several parts being replaced: a panel with a thermostatically controlled fan in the FREEZER and a new circuit board. "Thank you very much, glad we could help".
***>The problem was NOT fixed. Refirgerator section still froze things set at 37F. I reset the refrigerator to 43F, and a day later, I took careful measurements (accurate thermometer stuck into lemons on each shelf and in each drawer. Readings went from 38.8F at the top shelf rear (4.2 degrees less than set) down to 33.4F (nearly 10 degrees lower than set!) in the bottom compartments. So much for the advertise eveness of temperature in the advertising.
I escalated the problem. A 4th visit was scheduled. Same tech returned. He replaced the panel in the back of the freezer for the THIRD time (the freezer had always been rock solid at 0 degrees F as set). This time, he also replaced a similar panel in the back of the refrigerator!
I am guardedly optimistic that the problem has now been fixed. Top shelf temp measured 36.8 when set at 37 at the door, and there is now only a 3 degree variation (versus 5+ previously) to the coldest place in the fridge at the bottom.
My advice: use specific language when describing issues to the telephone rep. "Freezer overcooling", "Refrigerator overcooling" seem to trigger specific parts being sent with the repair people. If it's a temperature related thing, insist that the technician MEASURE the temps during his or her visit. Our technician had a rather fancy and expensive looking laser enabled digital thermometer gun which he used to take temps at various points in the refrigerator (confirming my lemons tests BTW). Insist that the technician verifies that the newly installed part, or newly done fix, works. When the new refrigerator sensor/thermostatically controlled fan panel was installed, I was able to hear, for the first time, a very faint sound of the fan working, doing its job properly. There should be SOME way that the tech can verify the efficacy of the repair.
Hope this is helpful to others. It's been a real slog, taking several months, losing too much food at our own expense. Now that the unit is working properly it really is a very nice refrgerator. Samsung has done the best job of any of the manufacturers in getting every square foot of storage out of the 36" double door footprint. Fit and finish are also very nice. The unit is quiet, and it makes enough ice for us. Too bad the warranty repairs were botched so badly. I hope Samsung and HSN can improve the quality of service. From my experience, that's something that should be a priority.