If your 210 is under warranty and/or you would like to have it serviced by Panerai, I would take it to Shreve & Co. who is an authorized Panerai dealer. They, in turn, will send it to Panerai's service center for the repair.
If it is out of warranty and/or you would prefer to use an independent watch repair service, I would get in touch with Geneva Watch Repair on Post St. and explain the problem. I have not used them myself, but I know of several others who have and they come highly recommended.
I hope this helps...