Metro PCS Did not refund Overcharge Layton Utah

On 9/6/17 my husband, daughter and I went to the Metro PCS store at 975 N Main street in Layton Utah to upgrade my husband and daughters phone.  The customer service we received from Liam was great.  When we got home I went over the receipt and noticed I was overcharged for my daughters LG K20 phone by 20.00 plus 1.38 in tax.  On 9/7/17 I called the store and spoke to Liam, he said his supervisor was the only one authorised to reinbuse the money back to my card, he said she would be in at 3.  I called back after 3 and Liam said she would be in between 330 and 4, she was picking up phones from another store.  I called after 4 and was told she was with a customer and would call me back and he asked for my number.  She never called, I called throughout the evening and got busy signals, I believe they took the phone off the hook (for 21.38).  So On Friday 9/8/17 I called Metro PCS Customer Care (they pride themselves on there cistomer service).  I was on the phone for 27 minutes on and off hold while they tried to figure things out.  The Supervisor Everett #62012 got on the phone and said only the store can reinburse my money but they can report them.  In otherwords your screwed and out $21.38.