You can always ask for the case to be escalated if you stall out. Whenever you are doing upgrades, let your SE know ahead of time (we hate getting calls for something we didn't know was happening), and you can also open a proactive case and pre-load it with all the information about what you are doing.
*** ALWAYS include the following when opening an SR ***
cpinfo from management and all devices involved. ***This is always going to be asked for***
A "show configuration" from all devices involved.
A "migrate export" of the manager.
I will normally open the ticket online, add the above, then call into TAC.
Aka, Chillyjim