Starbucks had a little bit of trouble over Memorial Day weekend. Over one million customers were overcharged for their coffee drinks on Friday, May 22nd and Saturday, May 23rd.. How much? They were charged twice for each purchase. The charges were accidental and due to a computer banking glitch. Starbucks is working diligently to correct the problem and reimburse the customers who were overcharged on their debit and credit cards. May customers do not know that they have been overcharged because the overcharged amount did not appear on the Starbucks receipt. It does however show up on the customers credit card statements.