My DD has been using her new MM 530G since Tuesday and we are really struggling. After reading a lot of posts here, our own experience, and doing some other research, I am considering sending it back and looking into the Dexcom instead. No matter how often we calibrate, or how steady and in range her BS is, the monitor is still so inaccurate. I calibrated for her this morning and she was steady and in range. She just texted me that the CGM said she was at 64, but she was actually at 32! That is a big, scary difference! I checked the Medtronic website and the return policy says returns "should" be unopened. Does anyone have any experience with returning a pump that they have tried out that did not meet their needs? We have had the pump for more than 30 days, but that is only because the rep thought that our insurance had already approved it and sent it out in error and we held on to it until we were sure that insurance had covered it and then did the training. Now (after we were told insurance had ok'd the new pump) we received a bill for $1850 additional, after already paying a $870 copay, and when I phoned Medtronic they said that insurance was only covering 50%. I asked what they had covered with the last pump and she checked and said that they had covered half, but Medtronic had covered the other half. I told her that they had better figure out a way to cover the other half of this one too, because we never would have switched from her perfectly good pump if we had known that we would be paying more than $2700 out of pocket! I am very upset by this whole experience, and frustrated by the inaccuracy of this CGM!