I have a GE side by side frost-free refrigerator and the freezer has ice on the back of the inside can you tell me what is wrong. Model number GSS201EMA CC.

The defrost timer switch needs replaced. Mine used to do this. I had to replace the switch twice before I got a "good" switch.

With it being a ge I would check the Glass heater in the freezer part behind main cover... do a ohm check on it