Be prosecuted for illegal gas connection. Urgent help

[Eaturbo]

Need some urgent advice. I was getting $615 gas bills for hot water only for only 82 days. Made several complaints to real estate as its a rental and origin gas and told it was normal and stiff. Disconnected the metered gas and hooked up a 9kg gas bottle with a regulator and used all proper gas fittings and LPG thread tape. Department of natural resources and mines came around and seized everything and interviewed my wife and said that I will be prosecuted in a court of law. Now apparently I can perform any and all gas work on my bbq because it's a mobile device but doing the exact same work on the house is illegal with a max penalty of $20,000. There is nothing near the gas system warning people of the law and possible penalty.

They bullied and intimidated my wife as I was at work and they never asked for consent to perform the interview. Can't believe such a simple mistake can be so serious with no attempt to educate the public or warn them of the danger. Not to mention that the exact same set up on my bbq with the same 9kg gas bottle is deamed safe even with an open flame and an igniter but the gas hot water system is illegal even though there is no naked flame even close.