You can turn to beginners who develop chat bots. Or you can apply to companies, but the cost of development will be higher. This way you can find experienced developers in this field.
I agree with you. There are talented novice developers out there. Then such specialists get a job at huge companies and develop complex applications that we use every day. If you need an experienced company to develop such chatbots. You can apply to ChatBot Development company they specialize in developing chatbots of different complexity. For example they recently created a chatbot for an investment exchange.