A sales tax snafu at Walmart meant customers were charged twice

• Walmart accidentally taxed some Alabama customers twice after its system mixed up a tax change.
• Alabama's sales and use tax base rate on food was cut from 4% to 3% on Friday.
• Some customers appeared to be charged both the old rate and the new rate on purchases.

Walmart has begun issuing refunds after a mixup with sales taxes resulted in multiple customers being charged twice.