PITTSBURGH -- Mary Bach has been watching out for consumers for years.

The Murrysville woman is on the Pennsylvania Senior Service Advisory Committee and is a consumer advocate for AARP.

In April, she bought a pair of boys pants for her grandson from a Wal-Mart store in Delmont, Pa.

They were clearly marked on sale for $3.

When she checked out, Bach was charged $5.

She pointed it out to the cashier and front end manager, and she was charged the correct price.

Bach liked the pants and price so much she went back again for another pair.

Again she was overcharged $2.

She pointed out the error to the cashier again, and the price was corrected.

Over the course of a week, she went back a third time and the same thing happened.

Then her husband bought a pair of the pants and was also overcharged.

Finally, Bach bought a fifth pair and was overcharged again. This time she didn't point out the error. She sued.

Bach said, “It comes down to the responsibility of the retailer to charge correct the advertised price. Wal-Mart had a duty to take care of it. It’s electronic bait and switch.”

Bach was in court Wednesday.

A Wal-Mart manager appeared and admitted the store was wrong.

The judge awarded Bach $100 plus $64 in court costs.

Bach said, "If they had corrected it, it would never have happened over and over. They had a duty to take care of it."