I apologize because I am sure this is going to offend someone, but I find it very hard to believe that no character even came near your section in 75 min. Are you sure that you weren't at the buffet or bathroom when they came through? This restaurant has a very specific rotation that the characters follow in order to stay on target and they cannot backtrack. Being away from your table is one of the main ways to miss seeing a character.
Also, the characters do not "go on break". While they might step out for a few minutes, they do come right back. If you pay attention, you'll notice this happens about every 45 min. I will let you all imagine why this happens.
CP is one of the hardest dining locations for characters to work. It is busy and crowded all the time. Sometimes, groups are missed. When that happens, they do not bring the characters out of rotation, but simply wait for you all to finish your meal, pay your check and then take you to where the character(s) are that you missed on your way out of the restaurant. The servers know this is the process, but are usually very concerned that they will be tipped less because of character issues and so do not always provide all/correct info. Not to blame them though - the tip should be based on the food as that is what you are paying for - not the characters. They are free.