Actually you probably did it a favor by repotting it when you did. They are fairly resilient plants. The main requirements are excellent drainage, acidic soil, and not much fertilizer. I recommend only fertilizing when they bloom and then at a reduced rate. To provide good drainage, us a pot with a gravel layer above the drain hole and good air space under the drain hole. If your water is alkaline, you may need to use rain water. Also, a little HollyTone when it blooms will help keep the acidity.

My favorite guide on growing florist azaleas comes from Minnesota:

Care of Greenhouse Azaleas

Here is a link that might be useful: Care of Greenhouse Azalea