I'm sorry you're going through this. I've had the same thing happen years ago when it seemed like I was treating birds with tapeworms all the time. They are tough to get rid of.
What you need to remember about tapeworms is their "indirect lifecycle."
In other words, insects are the hosts for tapeworm eggs. Chickens naturally eat insects and the chickens becomes infected. Almost all types of insects can carry tapeworm eggs.
You have to do your best to eliminate insects where your birds forage, almost an impossible task.
You can pen your birds for a period of time and treat the areas where they forage by spraying an insecticide. Keep in mind that not all insects carry tapeworm eggs.
Discontinue the Valbazen treatment for the tapeworms and just use the Equimax.
Withhold the chickens feed for 3 hours prior to them going into the coop for the night. Water is ok.
The next morning, do not feed them. Go out to the coop and snatch a bird off the roost, preferably before sunrise when it's still dark.
Then worm the bird with the Equimax orally. Then let the bird go. Repeat this procedure until all your birds are wormed with the Equimax.
Your birds will be starving, so will the tapeworms. The tapeworms will be weakened due to the lack of nutrients from the feed that was withheld the afternoon before and the next morning, making the wormer more effective in eliminating the tapeworms.
Do NOT feed your birds until 3 hours after worming them with the Equimax.
You might see strands of tapeworms, pieces of tapeworms or jellyfish-like tentacles excreted during the first hour after treatment.
After 3 hours are up, only feed your birds a little at a time, gradually increasing feed rations throughout the rest of the day back to normal feeding. If you dont do this and just put out the feed, your birds will gorge the feed possibly causing impacted crop or impacted gizzard or even swallowing feed down the trachea.
Follow this procedure, it's a very effective way of eliminating tapeworms. Good luck.