No Availabilities and Very Over-priced. Very Bad Support
They don't mention anything related to date restrictions on their site, but when you try to book, there are only limited dates that can be chosen in addition to being A LOT more expensive then the vendor (i.e., a booking which costs 160 euros on their site costs 245 euros, that's even without offering the same dates.
In addition, the support sucks, you try to contact them, but it's nearly impossible (no phone, just FAQ articles which don't really help) and the responses on emails and chat seem automatic (a really bad programmed AI) where your options for any question is "1 - Si, 2 - Si" or answer not relevant at all to the question
Reply from Smartbox España
Dear Customer,
Your feedback helps us to improve our service, thank you for contacting us.
You can contact our Customer Service team through the form that you will find on our website in any of the articles in the "Help" section.
Best regards
Smartbox Team.