By nature I am a grumpy old man who always complains about big organisations ripping you off. I had two bits of better news recently. Without going into details Microsoft were very understanding (when I finally got through to the right person) about some payments that I wished to see refunded and so were the War Records people who had taken advantage of an auto renewal system. So it's not all bad news if you are willing to persist.
Bonhoeffer uses a similar phrase 'worldly Christianity'. It's J Gresham Machen that I want to line up most closely with. See his Christianity and culture here. Having done commentaries on Proverbs (Heavenly Wisdom) and Song of Songs (Heavenly Love), a matching title for Ecclesiastes would be Heavenly Worldliness. For my stance on worldliness, see 3 posts here.