I trade a lot of otc. I've seen it with my own eyes. When you put an order in and the cdel keeps your shares. They manipulate it. I know this and try to use their manipulating against them. I switch from cdel to csti for that very reason, less manipulation. Cancel the bid and resubmit the order until I don't get cdel.
One way to check if they are going to manipulate when say you are selling a stock. Put a sell order in, then cancel. If the order goes in, but when you cancel, it does not leave, it stays at 1000 shares at that price. They were planning on selling for themselves with your order. You were never going to sell the shares! They were using your order for themselves!