Unisex Adult Matte Graduation Cap with 2024/2025 Tassel for High School and Bachelor

What is the size of the top of the cap , is it 10 or 9 inches ?

I have earned a doctoral degree in psychology from california southern university magna cum laude. what should be my colors (robe, hood, and tam)?

can I get a gold tassel on a black cap?

Who do I contact to fix the order? I ordered a tassel with 2021 and received a 2022 charm on the tassel instead