Confused Houseplant

When I bought this gardenia last summer, it was a very healthy looking plant - packed with glossy green foliage and large buds. Sadly, even though I tried giving it distiller water, more humidity, and plenty of sunshine, one-by-one the buds all withered at the base and fell off. Now, almost a year later, I find these beautiful, fragrant blooms popping out of a sickly, stick-looking plant. And all because I'd been too lazy to throw out what I'd thought was a lost-cause houseplant.