The date is usually on the ticket.
The box office is open daily and they do answer calls
Can try the box office. The box office gives tickets to other retailers to sell tickets, and they might be able to tell you... or you can find out through your credit card too
You can try if you bought them directly. If you bought them through a reseller I don't think the box office can help you. Can you check your credit card statement and follow up that way?
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