The RSPCA is the one blot in our area also. Some years ago my sister found a stray and tried to take it to the RSPCA but they told her they were putting their own dogs down (whatever that meant). Their adoption fees are much greater than Dogs Trust (which somehow still manages to never kill a healthy dog). As an organisation they currently seem more interested in power, politics and prosecutions than real animal welfare and I will not give money to them.
RSPCA and power to prosecute (too much power corrupts?)
RSPCA and prosecutions (persecutions?) of small animal sanctuaries (The RSPCA is still killing 53,000 animals annually in the UK and apparently is happy with that)
I do have a rather hilarious story of an RSPCA incident. When a friend had a very old and skinny cat it was kidnapped by a woman accusing him of cruelty. She refused to believe it was being treated by a vet, even refused to believe the vet existed, and reported my friend to the RSPCA. An inspector collected the cat, doubtless making sympathetic noises to the woman, drove along the road and handed the cat to my friend! The inspectors are often very good. It is the organisation that has gone wrong.
They really should get involved with the "just one day" campaign, after all they are expert campaigners why not put a bit of extra effort into homing the animals they would otherwise kill?