How can I retrieve my Apple Watch Fitness rewards after unpairing?

I tried the Apple Watch and paired it with my phone. After deciding it want for me I’ve unpaired it. That was in early July. I earned the monthly challenge award, but it isn’t showing on my list. I haven’t missed a monthly goal in three years (just with the phone).

Is there a way to get the reward to show?

[Re-Titled by Moderator]