usb broken

We need to know which system (L501x, L502x) and which port - it will either require a circuit board change or a complete new mainboard.

L502x. Right port broken and behind port broken. My left port still okay but i think the left and the back is connected, thats why my left usb port also cannot use

If they're physically broken, this is the part to replace:

http://www.parts-people.com/index.php?gt=c&action=item&utm_expid=6199460-12.iwtwpicjskq7kgd2vjjjdw.2&id=11198&utm_referrer=http%253a%252f%252fwww.parts-people.com%252findex.php%253faction%253dsearch%2526search%253dxps%252bl502x%252busb

If they are not physically broken, be sure you've installed the USB 3.0 chipset drivers:

http://www.dell.com/support/drivers/us/en/19/DriverDetails/Product/xps-l502x?driverId=WNN71&osCode=W764&fileId=3277996057&languageCode=EN&categoryId=CS

Sorry to ask. But that should be my left port right? How bout my right port? eSATA port? 

And, if i can recall, i dont see separate board on my laptop, somehow, the usb connected to motherboard and i ask the technician if they can replace it but they said they cant because my port is the stick, not the screw and unscrew thing. U get what i mean?

I can't make sense of what you've posted.  If you've damaged the USB port on the mainboard, then you will need a replacement mainboard.

I dont know whether my port connected to motherboard or not. My laptop is Dell xps l502x. Do you think my kind of laptop, its usb port connected to motherboard?

It looks like the USB/eSATA combo port on the right side is connected to a daughterboard.  The others on the left side are part of the mainboard.

what do you think i can buy the cheapest part to repair all of em? please. 

Try parts-people.com.  If it's a daughterboard, it'll be $50 or less.  If it's the mainboard, $200+.

Please help me