Sorry that happened to you...you definitely got a CM who was not optimally skilled, unfortunately. Another DIS Member mentioned upthread that you have to call to be able to book both, so I did. I explained to the CM what I was trying to do and he said, "No problem...I have the ability to bypass the block on MDE that you don't." I was afraid he would think I was strange for wanting to book both, but he didn't question it at all! I actually already had the fireworks parties booked for both
MNSSHP and
MVMCP, so I had him add on Tony's/Cruella's for our dates for me. It actually took longer for him to read all the fine print (he said it's required) than it did to actually book it!
I'm so sorry you got a CM who was unfamiliar with how to do this...it's happened to me before on other things, and it's really frustrating. Hopefully you can call back and get a different CM who can take care of it for you.