not receiving any incoming calls

I am able to make outgoing calls but no incoming calls are happening. message call failed from the phone making the call, and either;
a.congestion
b. busy
on the call history. I have tried changing from www3 to www1 but this has not worked.
The DID is mapped to sip/pbxes.org and the DID provider confirms that all is good at that end.
Help please

RE: not receiving any incoming calls

Hi,
what kind of tests did your provider made?

Usually they send SIP OPTION request to the registrar domain, and pbxes.org answer correctly to them.

This is my working configuration
DIDs forwarded to account_name-extesion@pbxes.org
inbound route: account_name-extension