First, I'll start off by stating that force-feeding should be a last resort method only. There's hardly anything more stressful to an animal than to be restrained, its mouth opened up, and food pushed into its stomach. If it makes any kind of effort to eat on its own, it should not be force-fed. The force-feeding can often lead to more problems by inexperienced people, and usually does not help the situation or correct the causative problem.
You mentioned nothing about the animals set up. The vast majority of problems with captive amphibians and reptiles are directly related to their husbandry. How large is the tank, what is the substrate, what is the water source, what kind of furniture is available in the tank?? Are you providing any vitamin and mineral supplements?? These are all very basic questions that should be explained.
There are many reasons for an animal not wanting to eat. At this time of year it is most commonly associated with the changing seasons, where most animal slowdown and stop eating normally when they are out in the wild. There can be several other problems such as parasites, infections, bad water quality, and overall stress that will keep an animal from eating.
What you should have done when you realized one of the toads was not eating, was too separate it into its own container in case it did have something infectious, it will not continue to contaminate the rest of the container for the toads. You should have tried different types of setups including substrates, either coconut fiber or simple paper towels. You should have tried raising the temperatures since their appetite is directly related to their body temperature. You should have also provided artificial full-spectrum lighting with the 12 hours on 12 hours off cycle. If none of these things helped, it should have been tested for parasites and treated accordingly. The parasites can easily accumulate in captive animals and one of the first indicators of parasites overload is a loss of appetite. The vet could have also done a skin scraping to check for pathogens. During this time you ideally would have been keeping track of its weight. If it had lost more than 10 to 15 percent of its original body weight and there does not seem to be any cause for its anorexia, only then should it had been force-fed. If you have to ask questions such as "how much should be fed at a time? What should we feed it? Should it be fed more often in the day?", thing you should find someone else with more experience to help you.
My advice for now is to stop force-feeding it, separat it into its own container and try some of the things I listed above.
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...the oldest task in human history: to live on a piece of land without spoiling it."
Aldo Leopold (1938)
"Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us."
Calvin and Hobbes
