Did I mess up my fp+?

[mich44]

I made my FP selections for our trip in June including one for Anna and Elsa. I had no idea that you had to keep 3. I canceled one of my other FP to free it up for other people. I called and spoke to a Disney internet help person and he said there is nothing I can do to get that 3rd FP back without deleting what I have. He even said it was to risky for him to try because he might delete my Anna and Elsa FP. Is there anything I can do? I want to add Wishes when it comes out.