Family Dollar complaint: Coupon and Deals

I shopped at Family Dollar today in Rosamond, Ca. on December 13, 2020. There were Red Tag Sales that listed all Socks, Underwear, Intimates, Thermals and Beanies and GlovesMittens as (Buy One get One 50% Off). I had also used the Family Dollar App to be able to Clip the Smart Save Coupons. The Manager happened to be the one who checked us out. He Scanned my Phone for the Clipped Coupons. My total was way more than it should have been. The Manager Voided the Entire transaction so that he could start over. He went and Removed the Red Tag from the Aisle where I grabbed my Items from. He said that; that Specific Deal had ended on 12052020. I informed him that it was not my fault that the Red Tag had not been removed and that he had to Honor the Deal. He understood and agreed. He then proceeded to rescan all of the Items. He would scan an item and then put in the price that was listed per the Red Tag. I was very pleased with my total at the end the second time around. He then scanned my Phone so that I would receive the Coupons that I had Clipped thru the Family Dollar App. However, after paying for my Items and walking to my car to put the Items in . I discovered that I had not received my Coupons the second time around. So with that being said I should have saved almost $9.00 off of my Final Total and I did not.
Thank you,
Miss. LaCie Koepcke