PIC programming - Get value of multiple buttons to a port
First of all you need to configure your input and output correctly.

You used TRISA = 1; which means only RA0 is an INPUT. Please change this to TRISA = 0b00000111; or TRISA = 0x07; to configure all 3 buttons as INPUT.

Same counts for TRISB. Change this value to 0x00000111 or 0x07.

As Peter has mentioned change all your cases on the switch to:

case1:
 // TODO
 return;
case2:
 // TODO
 return;


Besides, I don't even see where you scripted what the MCU has to do when a button is pressed?