Uber robbing a pensioner in a wheelchair

Recently my dad used the App to travel back home from the hospital. The driver collected him and dropped him, but instead of stopping the trip when he was dropped, the driver continued another 15kms and charged it t my dad. I then bought it under the customer care's attention and they apologised for the "longer trip". They then sent a message stating that I would only be charged the correct price and the difference would paid back to me within 3 -5 business day. Well it's 21 workind days later still no refund!!! My dad is a pensioner, in a wheelchair and can't afford to lose money.