Snails always seem to get shocked during acclimation. Assuming you did a good acclimation, they will come around soon. Given the amount of time they have been in your tank, this is perfectly normal. Actually, in my tank, some mexican turbos that have been there for over a year regularly congregate so that all of them are bunched up on each others shells. So, the issue really is that they haven't moved, not that they are stuck together. Give them a few more days.