Whether they were confirmed or rumored to, you're always free to send in a ticket voicing your suspicions or concerns. Of course, these hold far more water if there was substantial evidence backing the claims like screenshots or chat logs, but even if it's a suspicion, it can be investigated.
Just reminding again though, that gold selling and buying are not only BANNABLE, but that most gold sellers WILL ask for access to your information. This compromises your personal information and your bank account, and you'll be more likely to be hacked or be a target of other cyber crimes, which include financial ones. Aeria doesn't just ban offenses like this because it's not a good practice, but because it's an unsafe practice that can indirectly or directly affect Aeria. Sounds cruel or unjust in some perspectives, but this is what's done in order to secure stability for oneself. This is also why gold selling is bannable offense; it's bannable for the player's sake to not engage in harmful activities.