It doesn't matter if the billing people browse this forum or not, the ticket was opened and personally if one of my coworkers or my company had a disgruntled customer. I would let them know and try to get it taken care of, even if it fell out of my area of expertise or work. Sofar I have gotten another canned response about SLA's and nothing done to help resolve this issue. I was at work during your hours of phone operation, which I have to watch my phone use at work for personal matters. I don't even have access to personal mail at my work. I tried to email one IPS management member here but his email is private and if you try to send him a personal message it comes back with an error.
As for the queue of tickets, maybe you should have more detail about the queue. Example you are 4th in the queue, again its all software and could be easily automated and you are a software company. Then I could take screen shots and ask why I have been 4th in the queue for 5+ hours, but we know the answer to that. it's easier to hide behind the unknown and your SLA response.