OP, you might want to check your transaction history in blockchain.info wallet to see what address you actually "received" the funds to... also, you can find all your addresses here:
Settings -> Addresses -> Click 'Manage' next to "My Bitcoin Wallet/Default" -> Click 'Show' next to "Used Addresses" -> Click 'OK' on the warning dialog.
...
It is a good suggestion for the OP to check his HD wallet's addresses, but is unlikely
to be the issue. If the OP provided the "received address" to the ponzi site, it would send
to the address provided and not the next blockchain.info address generated in the OP's
wallet. The ponzi site wouldn't know all of the OP's addresses unless the OP provided his
XPub key.
It is very likely that the poniz is reporting withdrawal transactions that are all fake and all
controlled by the ponzi itself.