GNC locations in Charlotte, NC

GNC at the Village at University place, 8662 J W clay BLVD, charlotte, nc.
Horrible Store manger: Rachel New #Rachel New
Store number #5235
Horrible customer service experience for the second time at the same store.
Hope you dont' delete this review and I will post it on other places.

I am GNC customer for last 10 years. I am gold member of GNC.I use it because I get good discounts, not that I cant find those products out of GNC or other places.
I visited the GNC store number 5235 at the location Charlotte, North carolina.
I purchased two products on black friday, 11/272015. I did not receive the gold member discount coupons by that time which I receive every month by mail. Before the purchase, I asked the guy("Anthony) at the counter that day, that I did not receive the coupons yet, so can I come back and add the discount to my purchase when I receive them. Anthony, name which shows on my bill who was at the counter and did my transaction mentioned that I can come back and add the discount when I receive my coupons . I received the discount coupons from GNC on 12/02/2015. The two coupons that I received from GNC starts from 11/24/2015 till 12/28/2015.
The two coupons that I received from GNC are "Take $10 off any purchase of $40 or more " and "Take $10 off Any Whey Protein purchase of $20 or more" . I did two purchases , one is protein and other is clear muscle. Both purchases costing more than $100 each and total more than $200.
On 12/06/2015 , I took my receipts and the coupons ( sent my GNC, which I received late by 10 days) to the store and asked them if they can adjust the coupon on my purchase.
The guy at counter said he doesn't know how to do that , so he called this manager named Rachel New, Store manager. The guy at the counter explained to Rachel New and she said she will not accept these adjustment/coupons, which are still valid coupons sent by GNC to gold members. She did not agree to do that. Then I asked , if I can talk to her and explain . I told her these are valid coupons sent by GNC and I asked the guy when I did my purchase whether I can adjust , he 'Anthony'( guy when I did purchase ) said to come back and they can adjust.
She told me , she(Rachel New) not going to accept the GNC coupons and asked the guy at the counter to close the register on me. I got angry and I mentioned if you are not adjusting, I would like to just return the product, as I am not satified. Then this horrible store manger said to that guy at the counter to close register on me and not to accept the coupons and the returns.

Rachel New was very rude to me as a GNC customer and she didn't step up to take care of the situation than made it worse.
Unfortunately with GNC there is no complaint department I could go to, because I tried once when I had bad experience at the same store.

After asking for the contact info to talk to report my concern, the guy at the counter gives me a phone number , which goes to store locator. Then I went back and asked again for the right number, he gave me some number whom he says is the number of the Area Manager of GNC , David Klann. I left 2 voice messages and message to him and there is not even a courtesy call.

Being a GNC gold member and customer for 10 years , this is very bad experience that is making me go away from you.
Again Rachel New is horrible at handling the situation. Horrible second time bad experience with the same store.
I would think five times, if I ever want to go back to GNC with this poor customer experience.