After buying the voucher merchant won't accept and Cobone don't even bother to reply on email as customer care number doesn't work.

They are a scam because they do not have a client focussed refund policy.

Don't trust this company COBONE.COM and this website. They are giving you promotions which is not exist and never return you your money back. All hotels are booked before they post any offer. Be aware, call to hotel first to ask about offers. This is scammers website. You will never return money back and never get any promotion and service.