They are definitely scammers.
I have waited several days for withdrawal to be approved, then messaged the support, and after this they have blocked my account without any reasonable explanation:
Dear customer,
Thank you for reply. Due to system detected that your account existed abnormal transaction. In order to protect your account safety, your account login function was banned. Tech team need to check your account datas and transaction record. Please be patient. Once any update we will mail you. Sorry we cannot provide you an actual time or an estimate time.
Best regards,
RightBTC support team