the freezer won't go below 35 degreese?

The freezer is abourt 2 years old. Kenmore model NO. 253-26731203, s.n. WB72845901. The freezer gets cold but no lower then 34 degreese with the thermo. set on 7. I had a seare service man come out,and he said it has a restruction someweere and is not worth the cost to fix. How can there be a restructikn if it gets cold. Oh the freon was checked also, ok he said. I set the thermo to 1 and the comopresser stays on with the temp at 34. Is it possable to be in defrost and cold at the same time. Any ideas before I throw it away. I am experience in home and auto a.c. I'm not familier with the operations of freesers. Any help would be great.