I had my rear brakepads replaced in February by a Honda dealer doing an MOT. Afterwards I noticed heat and a slight burning smell. I've just been to Kwikfit for a front tyre and they've told me it looks like the rear calliper has seized and that there was a lot of brake dust. They think Honda may not have released the calliper properly when they fitted the pads and that this work would be under warranty Honda say that would not have happened and that the warranty doesn't cover wear and tear and any work will be at my own expense
In all honesty the chances are reasonably high that it could have been a mistake by the Honda dealer - unfortunately your chances of proving this and getting Honda to do anything about it are verging on non-existent.
It's ~3 months after the fact and calipers do seize on their own, add in that the car is now outside of the main manufacturer warranty and I think you are out of luck here I'm sorry to say.