Maybe you are not using the stable but the beta-version of JonDo and you are connected to the testing mix. In order to use it you need a different account which can be created free of charge, though. The payment process looks similar to the one you find using normal premium services in order to simulate realistic conditions while testing. Should you be annoyed by being asked for a second account, you can block the testing mix in JonDo any time you want or you choose the stable version, alternatively.

Another reason may be that your current account has expired or is empty. You may use an account only once.