It looks like BTC I sent to an address provided by Coinsquare (1GZYHu86gFAhbwWJxJ7jA8PqxpEy47kneC) was subsequently sent to another address.
I have no personal experience with Coinsquare, but it is an exchange. It's not a wallet, so you don't hold the private key to your deposit address, they do. Once you deposit funds to an exchange, the exchange uses your funds for other people's withdrawals. So far, this is not alarming.
... it has never been credited to my account. It's now three days, many confirmations, and they have ignored all attempts to contact them, including email to the co-founder/CTO.
As far as I know, Coinsquare is legit. Three days is annoying, but many exchanges take much longer to respond. Costumer services seem to be understaffed in many exchanges.
I cannot figure out how this happened unless it is a result of a bug in their code, or if they were hacked and I am a victim, or if someone at Coinsquare is stealing BTC? Any ideas on how to recover it?
The only way to recover it, is through Coinsquare.