After extensive testing with our provider we believe we have identified a fix for the issue.
We would request everyone who has suffered from the problems with the telephony system to reboot their handsets by unplugging it from power and plugging it back in. The handsets will pick up the new configuration file we have sent out and work as intended.
We would like to thank everyone who has provided us examples and the data that was sent was invaluable to resolving the issue. We apologize again the issues suffered and thank you all for your patience and support.