why tranny quit working after filter change and new fluid

What is your question?

How come my tranny doesn't go into any gear and it did before I changed the filter and fluid it's a 2001 C320 when I drained it it was real dirty and it was shifting funny so I changed it and now it won't do anything when I dropped the pan I got 2 1/2 quarts of fluid out of it does that sound about right

How long has your 2001 Mercedes-Benz C320 had this problem?

Just happend