Riots "Rune Refund" conversion is unfair!

I had spent over 1m IP in runes (~500 runes accumulated). After the conversion I was refunded with 70k BE which is less than 10% of what I actually spent. Riots reasoning is that I had time to use the runes and therefore the time spent playing with them is basically what was paid for.

Were runes not something that people chose to collect? what else was there to spend your IP on other than champs? To access your runes in client you even have to go through the "collection" tab, why the hell would you name it a collection tab if you won't even let players collect. Like many others, I bought my runes in the first place as an investment and not to get pennies back for them.

I believe Riot should further compensate players who had purchased at least more than 500k IP in runes. Thoughts?