There is no way that you deserve this Ashleigh, it’s a difficult one to reply to because there are of course two sides to each story and we are not really aware of how bad the little fellas ears were – for the RSPCA to make this sort of decision i would hope it was a qualified decision as i haven’t really heard of stuff like this happening before when the RSPCA are involved. It is a sad time for sure as i have just gone through the loss of a pet and the worst thing about it for me were the kids and their reactions, time will heal your hurt i hope.
I would suggest that if you were to get yourself another cat in the future, just make sure you get a microchip in place purely so that this sort of thing cannot happen again, really sorry for your loss and current sadness but it most certainly isn’t your fault so please do not blame yourself.