Help 3g problems

My epic keeps loosing its 3g data connection. This pass week I was on the phone w sprint (3 techs, 2 suprvsrs AND 2 hrs later) many resets, removing of 3g and reinstalling, etc and end result was send me a refirbished phone which I would not agree 2. We have a airwave in our home so I feel problem with sprint. Does anyone else have this problem or fix?