I have seventeen offices total. Two of these offices can call each other and it's considered a local call, although they're in different NPAs. We just installed a new PRI from a new carrier in one of these offices. This other office was unable to call them after that. They just got RELEASE AND TRY AGAIN. New carrier told me that happened because old carrier didn't release all the DIDs in their range. But if that was true, how come all other fifteen offices were able to call new carrier PRI office with no problem? I can't help but think that this was new carrier's fault. It took six hours for them to resolve this, and the CEO is livid and wants to know how it is this happened. Could new carrier have misprogrammed the NXX or something? Your assistance is appreciated. Thank you.