OP, Just keep trying to call back. I know it's a hassle, but we have all been through it. Continue calling and know that they have cancellations all the time and they will accommodate you if they can.
Don't just show up and play stupid--- think about how many people "playing stupid" the CMs have to deal with on a daily basis! Legions! They will see right through it, and you will be lucky if the CMs don't get an attitude with you-- which will not be at all magical. If they do let your entire party in PPO, it is likely you will not all be seated at CP, and the poor CM working the hostess stand will be left with an awkward situation by turning one of your party away. Alternatively, the CM may seat you (YAY! You "won"). This will mean other families, that have dutifully made their PPO reservation months in advance, will not be seated on time and their months of planning will be for naught.
See how unmagical this is getting?
Then those families will complain, managers will get involved, and the poor person working the hostess stand that let your party of 9 be seated will be called to account. Naturally she will explain that she did not want to face an angry, disappointed family, so she allowed you to be seated rather than risk a confrontation. At that point, the CM working the gate will be in hot water for letting 9 in on a reservation for 8.
Really not magical, is it?
So far this "playing dumb" has potentially upset or gotten into trouble at least two CMs and at least a dozen families.
I'm sure no one meant to impugn your honesty, but things like this tend to touch a nerve. Many of us have stood in line while people "playing dumb" try to scam the fast pass system ("But CM, I made all four fast passes! But only one is showing up in the system, I guess!"--guest "playing dumb with fast passes in an attempt to get more fast passes than other guests--all of whom have paid the same as the scammers.)
I applaud your wanting to give your family a magical, fun time. That's awesome! But none of us may run over others in order to have that fun time, and part of having a magical time is following the rules so that everyone else has the opportunity to have a magical time as well.
Be legit. Be considerate. Follow the rules. Call daily and hope for some pixie dust. I will keep my fingers crossed for you!

Good luck and have fun!