Oh my gosh! This happend to me twice before. Depending on the shop, they usually give you 20% discount or a shop voucher if it alarmed and it was their fault for not completely taken off the security tag.
You should have complained to see what compensations they could have given you?
I felt exactly the same when this happened to me! Grr.
Really? But I don't need their discount.
I want them to be more competent and give importance of customers' reputation! A written apology is also fine.
I sent my letter last monday and I hope it will not happen again.