Scotia Bank is a real bank, and yes, you can go inside during banking hours and use an indoor ATM. That's certainly the safest.
Lola, if they skimmed your credit card, they are using equipment (easy to buy) that reads the stripe on your card; probably a camera to get your PIN; and a machine to produce duplicate cards. Then they can simply produce several duplicate cards and send them out with accomplices who use them on schedule wherever they want, so as to get a bunch of transactions done before the account is closed. Not especially sophisticated.
I would say never to use a private ATM, and to be very suspicious in using any outside of a bank - including the walk-up ones outside a bank.