Problem with Accutron

Hello Everybody!

I bought Calibrator a few weeks ago and after a few minor adjustments it was running great. It was set by me one notch above the center bar and was losing about 2 seconds per day while gaining them back during night time while laying on the night stand face up. So, overall it was zeroed withing 24 hour period. It ran like that for two weeks and then something happened. For no apparent reason (no magnetic fields or hard impacts or drops) it started to run fast. Really Fast! I tried to set calibrator to the maximum negative position (-), but all I got was about 40 seconds fast per day. If I move calibrator to the max (+) it runs 2 minutes fast per day. I bought this watch from one of the Amazon's vendors, so they do not want to replace it, but agree to repair it under 2 year warranty offered by them. It is a hassle. But the thing is that I do not really understand what could have caused such a dramatic change in my watch's behavior. It appears that calibrator still controls speed of the watch, but at much higher than normal rate. Does anybody have any ideas or suggestions on how to address this problem? I have a big suspicion that seller does not really have much experience with calibrator watches, so I am not particularly happy about letting them poke around my piece. Although I may not have much choice....

Thanks.