They would never over charge,
I don't know how much money we are talking about here but to take legal action for might be more is worth I'm not sure how they overcharged you I would ask to speak to one of the girls in the front they're usually very good but I would go in person it can be hectic on the phone.
I'm sure if you just went in person with your receipt. a manager on duty would probably fix that for you really easily without you having to go through all the stress and hassle of taking legal actions
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