Shabbos afternoon, he told me that if this is what Judaism teaches, he is very disappointed.’
You were so out of line, the line is not even visible. First you get a teenager to WANT to be frum. When he is solid in his frumkeit, he might be more receptive to being taught what you meant well in teaching him. You were wrong, IMO. And I pray you didn’t so negatively affect this boy that he has no further interest in being frum.
This is a problem that I see in many such programs. KNOW your target audience and worry about the BIG details. The smaller ones will fall into place at the right time, but you have to get them engaged and interested first, before hitting them with the things that are important to you, but might not yet have any impact on them.