GNC return policy help.

Hello everyone I don't know if this is the right place for this post. If not I am sorry.
My issue is I just bought TESTRO-X Testosterone Booster 90 capsules from GNC.
But my Gym trainee told me not to take it. I know I could have asked him before buying but I didn't. But the issue is when I'm trying to return the product now they are refusing to take it back because it's been only 17 days and I haven't opened it. Due to lockdown, I was unable to return it on time. I have the original receipt and unopened product. They have mentioned on GNC return policy that they accept up to 30 days to return the product. I don't know what to do now.
whom should I call and talk to next to return it?

good