Hi @Sophie227,
I'm sorry to hear you're having problems trying to submit your payment info to make a booking. Have you tried clearing your cache or using a different browser? Chrome works best with the Airbnb website.
If it is still not working I suggest you contact Airbnb - this Community Help Guide gives advice on how best to do so.
Just to let you know, I have moved your post here to a new thread in Commuity Help - it will be easier for other users to find it here and hopefully also give you advice! I have given it a title, please let me know if you want this changed.
I hope you can get this sorted soon!
Kirstie