Natural England is the government's advisor for nature. The Environment Agency and local authorities deal with regulatory matters, environmental crimes and ensuring businesses (including farmers) comply with environmental regulations. While it is our collective responsibility as cavers to remove rubbish left by cavers, and ensure caves remain clean, the rubbish in question counts as fly-tipping and would be best dealt with by a regulatory body rather than caving volunteers.
I am not sure why the insults are necessary and why you couldn't just say 'I was of the understanding that Natural England dealt with these matters because...' in a polite manner.
Since you 'claim' to be a member of the BPC too, I suggest that if you have any concerns about me you can discuss them with me in person in the ale tent next weekend rather than on a public forum.