<human>: Can you provide a brief overview of the text?

We had to cancel a reservation with a caravan park in France, due to the fact that we found it impossible to rent a car due to neither myself or my girlfriend having credit cards. We planned our whole trip around the fact that we would have our own transportation. We arrived in France yesterday, and after spending a day trying to get hold of a car, no-one will hire to people without a credit card. We rearranged our trip and let the caravan park know that we would not be arriving this morning, along with our reason why. We have already paid a 90 euro deposit which we had to let go.

Problem is the owner sent us an email suggesting we weren't telling the truth, that they could have helped us find a car (despite our current guesthouse, as well as countless car rental companies, telling us we had no chance), and are now demanding we pay for the entire stay. A total of 210 euros in addition to the 90 we've already paid. I'm almost sure that they can't do this but was wondering if anyone could explain exactly why so I can add a little weight to my email.

Sorry for the essay, but hopefully one of you guys can help. This holiday has been stressful enough already. Thanks.
<bot>: Having paid a deposit with a caravan park, unforseen circumstances meant that we had to cancel last minute. Owners now want full amount. Can they demand this?