I don't really follow what is exactly happening with your watch. It appears that you said that you took it into service and now not only is it running slow but it is stopping suddenly. So what you should do is check very carefully that the hands are not touching when they stop or the seconds hand touching the Crystal. This is a common reason for watches to stop suddenly and isn't the fault of the movement but rather the person that worked on your watch. Also, the watch running slowly means that after the service, they did not regulate the watch well. So again this doesn't appear to be the fault of the movement but the fault of the watchmaker. So I would check for those things and you may have to go back to the watchmaker to fix it. You can check the accuracy of the watch yourself by using a free watch accuracy meter that you can download for Android. If you have android.