I’m having a hard time believing this is a first-time offense for breaking a rule the parents have decided is non-negotiable. That being said, be careful with the threats. Only threaten that which you are willing to follow through on. And, honestly, some of these so-called threats are more than that, they are viable options. The best option the way I see it is putting up one more solid argument to get them to sway. If that doesn’t work, do what @ClassicRockerDad suggested and lock them out of your account and finish your semester. Then, decide where to go from there. You’ve got time, breathe, don’t do anything rash.