How do I get my parents to be more respectful?

I came home the other night to one of my parents on the phone with "Apple Support" and it looked like the computer reloading after an update. This was at approximately 9PM so I asked what was going on. I was told that a call came in from Apple support detailing their computer had been hacked 47 times and assisted them by going to a GOOGLE HELP SITE to update the computer. The parent had been on the line for an hour already and was just waiting with this screen indicating it would be ready in 35 minutes. There was a woman on the end of the line constantly talking. I had to intervene to get the call to end and disconnect the computer. I changed as many passwords as I could. The parent in question kept claiming they didn't think they did anything wrong and had disconnected before the thing was completed even after I told them that wasn't the case. I told them to not use the computer until it could be cleaned in a few days time.  Thoughts, suggestions? My brain is fried.