Overcharged and not refunded the full amount

My daughter is in boarding school in Meadowdale, and she has one of my FNB bank cards, she ordered food from Mr Delivery and was charged twice, I went to FNB to fill in a dispute form, only to find that instead of refunding 195 that was overcharged they only refunded me with 95, I would advise people using them to be careful and check your purchases and bank statements