@ALLFORtheSMONEY
Practically every MSC has contact information listed on their website. It might be a phone number, email address or webform. If you need to reach someone at the MSC and the scheduler is not responding, you'll need to look on the MSC's website to find another contact. Or, you can search for the MSC on the board and you'll probably find the answer.
If the ONLY contact information you are able to find is the scheduler, then sending them an email detailing the issue and asking "if you are not the correct person for this, can you please let me know who I need to contact?" does wonders.
Or, you could simply post here saying what MSC you need help with and actually get useful information.