Possible scam exit. Still haven't received about 5btc
You removed the addresses, so we can't help you much here. How many confirmations are there for the transaction you sent Bitcoin to Sinbad?
I also suggest that you go to their official Telegram channel and ask this question.
https://t.me/Sinbadio_EnglishOmg, there is several receiving addresses, 2/3 - ok, 1/3 - not ok
I wrote them to
support@sinbad.ioIt could be. But, without presenting more concrete information or more evident evidence, you should not come forward and make accusations.
As mentioned, support returned from vacation on the 28th, there should be a lot of emails to read. You should wait a few more days to see if you get feedback.