I was stupid to call the scam phone number and let have remote access.

I already erased and reinstalled the is OS X yosemite but my question is if it's ok to use the computer for billing and buy online again? I've also changed all my passwords and I didn't give them any money cause I'm broke so they don't have my card number. But I also took precautions and called the bank and froze my aacount and I'll be getting a new account. I know no one knows what they may have seen when they had remote access, but I just wanted to know if I can pay my bills online or buy online with my macbook again.