Where do I find a Replacement plastic screw type mechanism that attaches the tube frame of a canopy to the tube frame of an outdoor 3 person Canopy Swing purchased from WalMart about 7 or 8 years ago?

My question is where can I get a part of the mechanism that is called a fixity. It is the part that has the teeth on the plastic that fits into the other part with teeth at the end of the pole to hold the canopy in place. I can send a picture if you need more info. my e-mail address is hugs@vianet.ca Thanking you in advance Huguette Perron