I did once take a 5ltr tin of B&Q white exterior paint back, it said on the tin no quibble refund if you are not satisfied.The checkout assistant noticed there was paint running down the side of the tin, and asked if I had opened it. I said yes, and I have used half, that is how I know it is rubbish. I had given a wall two coats and could still see through it. I said I don't want a refund, I would put the extra couple of pound to it and change it for a tin of Dulux. Certainly Sir.