Hi Val
I'm very sorry to hear your bank debited your card twice.
Unfortunately this is the kind of thing that can occasionally happen when cards are used. In my experience, I wouldn't say that debit cards are any more or less risky than credit cards.
And there isn't really anything any of us can do to avoid such mistakes happening, other than to never use debit or credit cards, but that isn't really an option nowadays.
However, I'm sure you will be refunded by your bank in this situation, as it sounds like an obvious mistake.
Kind regards,
Olly, your editor