The local shuttle bus (dolmus) departs every 10-15 minutes from the middle of the bus station, will take about 15 - 20 minutes to get to Pamukkale and if you tell the driver that you want to stop at Melrose House Hotel, he will drop you at the end of the street.
There are about 6 buses a day from many different companies. It should take about 6 - 7 hours from Ankara to Denizli.
Most buses are night buses, leaving every hour from 7pm to 10pm. There sometimes is a day bus that will leave at 8:30am. It should take about 10 hours.
There are many buses leaving all through the day and night. Most bus companies will say that the bus will go to Pamukkale, but only the Ege Koop company has buses travelling direct. All of the others (including the Pamukkale bus company) will travel Denizli. The Ege Koop bus leaves from Selcuk at 9:30am in the summer season It should take 3 1/2 hours for this journey.
There are about 5 buses each day from Fethiye to Denizli. The Camili and Golhisar buses will take about 4 1/2 - 5 hours for this journey. Pamukkale bus company has started a service that takes 3 1/2 hours.
There are about 4 buses each day from Marmaris to Denizli. It should take about 4 1/2 hours.