Was renting my villa in Phuket through TripAdvisor/ Flipkey. Needed to cancel ne rental because my villa was being sold. Could not pay their cancellation fee online: their app was turning down my payment and systematically ask me to call their customer service. I tried to pay more than 12 times on different devices: mobile, ipad, computer. Same results. In the end spoke to their customer service. Asked me to give my credit card confidential code over the phone which for obvious safety reasons, I refused to do. Then asked me to make an international bank transfer: they were unable to give the proper bank details (no account number, no full name of beneficiary). In the meantime, they were not canceling the rental which mean that their client deposit was not refunded, and the client was prevented to make other arrangement.
In the end, they terminated my access to the app, ending a multi year relationship with no incident so far, for the non payment of a cancellation fee which I was very willing to pay if their system add allowed me to proceed online.
Useless. I would have rated them below 0 if it had been possible.
Owners and renters: avoid them!