Disrespectful house owner

Went to my plot today to find the new residents of the house that back onto my plot have tidied their garden and thrown all their rubbish onto the back of my plot , we managed to confront him at over 2m distance he said yes some of it was his the leaves from his palm tree but the dead lavender,tree stump,fir tree clippings and all the soil wasn't his and I could go into his garden to prove it but I said that was no proof because they were now on my plot,when told about the soil that wasn't his either he said but there was loads of soil and shrivelled up plants on the 8 foot tall brick wall he said someone must have put it there to set him up.he said he saw my compost bin and thought he'd add to it, I told him it was my compost not yours and please desist from doing so again or I'll have him for fly tipping.So much for being kind to your neighbour in these times,my poor husband spent over a hour cleaning up his mess