subscription manager fails to register

Hi,

I try to register the system against red hat using subscription-manager register & once it prompts for my credentials it comes back with 503 server error since yesterday - and that was the time I tried to register it first.

I use proxy and I put the proxy information into rhsm.conf, and I always get back 503. I tried everything from the beginning from cleaning the subscription info and clean yum caches but always the same issue.

I tried to register the system offline too, using the registration assistant but once imported the certificates it had the status unknown state which was expected, then registration process ended up same as before.

Could you help me how can I resolve that? I'm not sure whether it's an account issue or what.

Thanks in advance.