Revolut has quite a big customer base in Lithuania and recently many articles have been published about people having their accounts frozen without notice.

Article in Lithuanian: https://www.delfi.lt/verslas/mano-eurai/revolut-klientai-pra...

The lack of in-person or even phone support is practiced by quite a few banking start ups. This also means that if they block your account for any reason (e.g. suspected fraud), it can be very hard to get hold of them. N26 has had similar issues with people not being able to access their money for weeks after their account got blocked.

Not sure where the rest of the accusations comes from.