Double charges

Just curious to see how many people have had double charges as a result of using Curve.
It’s happened to me twice in the last few months. Usually one charge and then another a day later for the same thing.
Just chasing up an unresponsive Customer Support for the refund of the second one…
I am on the free card, but this doesn’t inspire me to go for the paid tier…

Depends on the charge. Some merchants, especially airlines, hotels, … put an AUTH on a card and then later send an offline transaction and never remove the AUTH again and just wait it out for the AUTH to be expired. Luckily Curve removed unclaimed AUTH after 7 days, other Banks (i.e. Fidor) wait 30 days