"How do I leave the the training company without damaging them or me any further?" Face that there may be no way to leave without receiving a negative reaction from the client. Staying in order to avoid conflict is not a better choice. Nice or not they already know they are trying to get you to resolve their problem without investing any time in communication or any money in the tools and infrastructure resources you need to provide the solution. Making themselves available to you when needed is the very least they should have been doing. A working solution requires that the client be at least as interested in the success of their own project as their solution provider. Just say what you need to say and move on.