Deposited to unfamiliar address

I was making a Bitcoin deposit using Moonpay. I copied and pasted the address, so it wasn't possible for me to enter the wrong address, yet somehow Moonpay deposited into a completely different address than the one I pasted into the field. Does anyone have any guesses as to how this could have happened and what my next steps should be? I'm at a loss as to how to proceed or where the mistake was made. The address link in my confirmation email sends me to block chain and it has had no transactions before, so I'm not sure that it's owned by anyone.