Send a registered, written letter. There are legal requirements for written letters that mean MPs have to respond to them. I'm told that you should also ask a couple of disparate questions in the letter, as this means they can't simply respond with a form letter.

letter-to-MP tips https://www.efa.org.au/Campaigns/lobby.html#tipsletter

MPs are under no obligation to respond to a letter

Hrm. Perhaps things have changed? I was told a while back by someone closer to Canberra than me that there were legal requirements for responding to letters; email was a boon, because it wasn't subject to those requirements. My apologies if I've misled.

That's pragmatic, he/she made the calculation that you have little political weight. Chances are there are people who contributed to his/her campaign or who are members of the community with more pull, and that you and your family aren't part of that group, and current members of that group disagree with you on the topics you brought up to your member. Or maybe he just did the maths and decided that an hour's meeting would have a higher return on investment with someone else.

There's no easy solution: either you earn influence and use it to further your agenda (a la George Soros), or you try and build influence in some other way, such as publishing reasoned arguments in an easily shareable format, which is what the EFF is very good at. It's never been easier to have some impact.

There have been a number of web campaigns* initiated in Australia that have gained some traction. As you suggested, that's the best bet for the average person with technical skills and a way to get a concept to resonate with people.

* This is one example: http://howfastisthenbn.com.au/

It's not exactly in the mainstream media's interest to cover public opposition to this, either. For the most part, they have a vested interest in pushing this.