Illegal LPG gas water heater/parts missing

After discussions with Amonstar for a gas hose and regulator to be include in the purchase of a tankless gas water heater, I ordered one. When it arrived there was no hose/regulator in the package. i contacted them and was told it would be sent for another $42 AUD. They reduced it to $12 after more emails Finally saying they would send it free. However, while shopping for the hose here in Australia I was told that the water heater had not been approved by AGA and was therefore illegal - no-one would fit it for me. Amonstar would not give me a refund and after putting a claim in with Paypal and losing the claim, Amonstar reverted to demanding the postage cost to get the hose sent. Apparently when you lose a claim you also lose the right to give Feedback on Ebay, that option disappeared.