It is NOT THE RESPONSIBILITY OF THE FA TO LIFT BAGS INTO THE OVERHEADS. Period. The passenger's problem does not somehow cancel that out. Some FAs do help, but they are not required to (and are actually discouraged). Complain all you want about a FA not lifting the bag, The bag got into the overhead - it should end there. If noone was able to help, FA could have called someone who is allowed to do such work (like bag handlers).- if it got to that point - but it didn't. Let's not overburden the DOT with a triivial one-off "problem" that actually wasn't a problem. Did the bag get into the overhead? Yes, it did. Did the OP misunderstand the duties of a FA? Yes. Start complaining to the DOT if the bag and pax ddin't make it to the destination.

I, personally, am more than happy to help people get stuff into the overhead, as are many other passengers. Actually, I think that's some of th ebest human interactions on an airplane betwen passengers sometimes.