Nexus 4 wireless charger crazy heat issues

i bought wireless chargers and one heats up my phone much much more than the other, i tried with my other nexus 4 (i have 2) and in other another outlet plug and nothing changed, it also had started and stoped charging but i restarted and it stopped. What should i do, what are my options for returning it?? please help because i need the info asap because im from canada went on holidays in the states, bought it and if i need to return the charger most return quickly!

PlZ help and share your experience with it