Hi @Ashwin. Did you use ACC capitalized?
Another possibility with a BYO modems is that you may need to simply leave the PPPoE login/password fields blank.
If you've tried both of these and neither is working for you, you may need to get in touch with AGL support.
When you do get it resolved, it would be fantastic if you could share the model of the modem you're using and the solution that worked for you - this might help others using the same BYO device.