I got the filler from an online store, Hopdawgs.ca
I've been emailing them and Chris, the owner has been really helpful. After contacting the manufacturer we may have a solution:
just heard back from the manufacturer. The ball valves are not to have check valves. I suppose I need to get you a couple. I will get them ordered for you today. It usually takes a about 8-9 days for them to arrive. I'll send them out as soon as they arrive.
So it looks like i'll be getting a couple new ball valves. Hopefully that answers it.