It's not uncommon for most people to lose their cool sometimes, especially in an online tournament or competition. If your opponent behaves badly towards you, you should never respond in a disrespectful way. Instead, the situation will usually improve a lot by just being friendly or by ignoring their comments. Make sure you don't get pulled into a flaming war, if both you and your opponent are behaving badly it's much harder for an admin to resolve the issue.
Unfortunately, that will not always work, and toxicity is something we don't want on our platform.
All offenses related to toxicity or unsportsmanlike behavior should be reported via the Toxicity Report Form.
Once you've done your part and we've found the accusations to be correct, one of two things happens.
Depending on the severity of the case the user will either be issued a warning, if the user already has received a warning or if the case is deemed bad enough, the user receives a suspension from the platform. Two strikes and you're out.