Planting it in alkaline soil was not good. Azaleas like an acidic, organic (lots of compost), loose, moist soil but always with good drainage.

They aren't difficult if you have acidic soil, but certain steps need to be taken when planting them. It does sound like you made a good attempt to loosen the roots...if I come across one very root bound, I root prune it, cutting away matted roots from the side as well as the bottom. Planting them too deeply can mean certain death too.

What did you add when attempting to make your soil more acidic, because it sounds like it may have burned roots from your description. Your pink hydrangea unless several years old may not be a good indication of your soil ph - I know mine is acidic but pink hydrangea Pia remained pink for a few years before taking on a pink with blue overtones color.

And last, if this was a gift azalea, wrapped in foil from the florist...they really are not bred for installing in gardens and are often treated more as a long lived bouquet. The breeding concentrates on large numerous flowers that can be forced easily for particular holidays, and the steps in forcing flowers can be detrimental to overall plant health . If this was a florists azalea, it wouldn't have survived winter in zip 49047

AH! thanks for the tips, I'll buy an azalaea from a nursery next time, I have lovely loamy soil, because
I cover my beds with leaves each year and then visqueen to keep it from blowing away(holes cut in the plastic for the perennials, oc)
I have nice soil in my gardens now but I inherited sandy soil, it drains nicely but requires watering all the time. The amended soil now is dark and fertile and grows everything
I plant, except for the Azalea. Thanks again,
PL

Not only was the soil acidic, but if you added Aluminum Sulfate (which is what is used on Hydrangeas) the aluminum is toxic to azaleas.

If you decide to get a garden azalea, make sure you plant it in moist, well-drained acidic soil.

Here is a link that might be useful: How to grow azaleas.