Don't lose heart, there are several things that may have happened.
Some small amount of regrowth within a week is normal, particularly on first-time clients, and it tends to be more noticeable with very hairy customers and darker hair.
Was this his first wax, or has he been waxed previously?
Does he normally shave or use a chemical depilatory on his chest? If so, he will experience irregular regrowth for a few weeks and it will take 2 or 3 waxing sessions (spaced 4 weeks apart) to get best results.
If there is a lot of stubbly regrowth after 3 days, it may also be possible that some of the hairs broke during waxing and it is these that you are seeing. This can happen with tough male hair (and tough female hair, for that matter!), and the hair growth patterns on the chest can be so varied that it is possible to overlap some areas and accidentally remove hair in the wrong direction (which can also cause the hair to snap). Be extra vigilant with observing the directions of growth and super firm with your strip rubbing and this should help with a clean removal.
Keep him on a regular schedule of every 4 weeks, educate him about hair growth cycles and warn him of the possibility of stubble and irregular regrowth between his next few appointments, and I promise you'll start to see results.
Andy x
