After Greenhub purchases the academic package, the activation code is invalid and the subscription cannot be cancelled

[Yxu-boop]

After I bought the academic package in the Greenhub program, the activation code has been displayed in circles after being entered, and the activation code cannot be activated successfully, and then even the activation code is displayed as invalid. However, if the activation code cannot be activated, I cannot enter the package to cancel the subscription, and the expired credit card will automatically deduct fees. I cannot contact Greenhub. I feel cheated, and I hope to solve the problem as soon as possible