It’s possible that attempting to change your payout method was flagged as fraudulent, which may be expected in some scenarios depending on how exactly your payout information has been changed. Essentially, it’s possible that it tripped an alarm, there being a possibility your account was compromised and someone was trying to change your payout information.
If that is the case, I doubt a devforum post could provide much assistance to you. I’d recommend trying to reach out to support again or directly contacting a member of developer relations or someone on the DevEx team.