Picked up a flytipped item, what should I do?

[Fulbe]

I found a broken sink in an alleyway near our house. Being a responsible citizen I carried it home and tried to take it to the tip. Once there they told me I would be charged £8 because it's 'rubble'. I refused to pay it, but what else can I do?

AIBU to think of putting it back in the alleyway?

Exactly. It's DIY waste, not commercial construction waste.
Where is a householder meant to realistically dispose of DIY waste then?
Bit pointless of some councils restricting the tip to basically household bin overflows.
OP, dump it back where you found it or smash it up and dump in the bottom of your wheelie bin (then it goes straight to landfill rather than being handled in the most appropriate waste stream - but that's on them, you tried doing the right thing).