Dick’s Sporting Goods complaint: embarrasing experience at checkout

I was shopping at Dicks in Tuscaloosa yesterday around 3:30 pm. I went to checkout with a small purchase of $50 plus. The young lady range up my merchandise while also talking to another customer on the phone. I inserted my card but the transaction denied. She asked me to repeat the transaction which i did. the card denied again. She apologized and told me she had the same problem `earlier that day with another customer. She suggested moving to another register. The next register had the same rejection. I told the employee to forget the purchase that i would go elsewhere. I also told her this experience had embarrassed me . Her reply was don’t worry I won’t tell anyone. I am not kidding you. Obviously this employee has not had proper training and i would like to know where the store manager was. The untrained employee was the only employee in the area.