DIAGNOSIS The wand gets jammed on because fine dust and debris get packed into the locking mechanism on the handle. It's not broken, just gunked up.
FIX Don't just yank it. First, press the release button on the handle and hold it down. Then, give the wand a firm twist (like unscrewing it) while pulling it straight out. The twist action helps break up any caked-on dirt. If it's still stuck, take the whole unit outside. With the release button pressed, tap the connection point lightly with a rubber mallet or the handle of a screwdriver to vibrate the debris loose.
IF THAT DIDN'T WORK If twisting and tapping don't free it, you'll need to clean the mechanism directly. Look at the top of the wand where it inserts into the handle. You'll see a small metal button. Try to work some isopropyl alcohol around that button with a cotton swab to dissolve the dirt, then attempt the twist-and-pull method again.
HEADS UP Forcing it straight out without twisting or using the release button can break the plastic tabs inside the handle, which means replacing the whole handle assembly.