G E side by side defroster stopped working... replaced heater coils... worked about two weeks... freezer stopped freezing... food in refrigerator warmed... milk spoiled... this happened twice already in a span of six months(replaced coils twice)what is a solution??

Your problem is one of the following 3 items:

1. Defrost heater faulty.
2. Defrost limit switch faulty.
3. Defrost timer faulty.

Since you replaced #1 item would suggest you take a multitester and test #2 and #3 and change out that part.