It's hard to fully understand the background of your question, but in general, it sounds like you want this company to start a pilot program with your service. To get them to be willing to start a new pilot program with your service, you'll need to make something that solves the problems that existed with their previous service. To do that you'll need to better understand _why_ their previous service "did not work."

Was it because the service itself had too many bugs, or because customers didn't need the service, or because the user interface was inappropriate, etc.? Get as in-depth an answer as you can to this question. If possible, ask your contact at the company, ask the engineers that worked on it, and most importantly: ask the company's customers that used the service while it existed. You could reach customers by posting on forums (Quora, Reddit, etc.) something like, "Question for people that use [company X's] services"

Based on this info, you can design and build a new product which solves the pre-existing problems. Show this new product to the company's customers that you previously interviewed (through forum posts, etc.) and quantify their interest in it (rate 1 - 10 if you think this would be useful, etc.). You can then show your research, and new product, and how much their customers like the idea, to the company and you'll have a higher likelihood of them being willing to start a pilot program with it. If not, ask them why not, and see if you can address that issue as well.

If you'd like more detailed advice on the specifics of doing market research and product development for your idea I'd be happy to help,

best,

Lee