What I need to do with my code?
Nothing until you explain what this means:
and want every case to run for example 20 times
Each case should run when you press the appropriate switch on the remote control. If you want a particular case to run only n times, you need to count the number of times it runs, and then not execute the case code if the count has reached n.
The loop() function will always continue to run. You can make in not accomplish anything. But, why?