As per your records you have bought Lightroom 6 in April, which does not come under the return policy.
You can buy Lightroom CC subscription but unfortunately we can not provide you any refund for Lightroom 6.
Is it me or is it a bit bogus that Adobe holds back features from those who paid up front for the same software? If they do not wish to sell LR 6 as a single purchase - then don't offer it. The web seems to share the sentiment.
Actually, Adobe did not "hold back" any features. Lightroom 6 is sold with customers knowing (or should know) that it would not receive feature updates. If you want all of the features that are available in Lightroom then you need to subscribe to the creative cloud package. Lightroom 6 is sold in the same manner that previous versions of Lightroom were sold. There were updates to include new cameras. But new features have always been held back until there was a new major release.
Ok - interesting to know - so then the De-haze feature is something that came out after LR6 was released and added later as a feature of the CC?
Yes, that is correct. Also the blacks and whites sliders in the adjustment brushes and other tools was added later. I suspect that when Lightroom 7 is released at some time in the future those features will be added to it. But it will be a paid upgrade for standalone Lightroom users.