Proof of return / disposal of car batteries

The battery in my car has now blessed the time. When I bought this battery a few years ago I had not paid a deposit, because I had directly returned the defective in the trade on site. This to the background. Now I have bought online a new battery. There was of course a deposit included and I would like to get this refund. For this I need a proof of the disposal of the old battery. So I am with the defective battery to the dealer where I bought it. result: free withdrawal yes, but does not provide any proof that I have returned it! Then to the recycling yard. There it was said, one does not accept car batteries at all. Another dealer did not want to accept the battery at all: “That is not bought from us, we do not take it back!”. On the way back then still drive by the scrap metal. Also there you do not want car batteries. Now I have read something about the topic and as I understand it, every handler is he who also sells car batteries himself is obliged to take them back – no matter whether they were bought there or not – and also to issue a proof about it. I find this actually a cheekiness like “zicky” behaves in particular the retail trade, which also sells the things. Who is then contact person or there is an authority which supervises the compliance of the battery law?