SIPSTATION inbound from pstn call problem. 7 digit dial within same area code not available?

I have several sipstation trunks and DID’s in the same area code.

When someone calls my DID’s from a landline in the same area code with a 7 digit dial, the call does not complete and they get an operator message informing them they must first dial a 1 or a 0 and the area code to complete their call.

I need to know if there is anything that can be done to remedy this, or if this is simply a limitation of the SIPSTATION trunks & DID’s???

I have debugged the trunk in the asterisk cli and I do not see any log entries whatsoever for those inbound 7digit calls that did not complete.

SIPSTATION support responded to my question without really answering it directly. They informed me that DID’s will be delivered in 10 digit form, which is fine but that doesn’t tell me whether or not they have a dialplan problem upstream from me or not and whether they can handle 7 digit dials in the same area code or not.