Pizza Hut *****ing from a pensioner

2 months ago, we ordered pizza. My mom, a pensioner offered to split the bill with my husband. The driver had a problem with the card machine and did mention that if anything went wrong with the payment, they would call. A second payment went off my mom's credit card. We called in, shared the detail and where promised that the second payment to mom's card be reversed. My husband has proof that the payment went off on his side as well. 2 months have gone by and a pensioner is footing the bill of the extra interest accumulating on the additional payment. At which point does Pizza Hut acknowledge the error and assist the client and by so doing refunding the pensioner not only the payment but the interest accumulated. The service has been shocking even with a follow up to done by myself. I do sincerely hope that this message is attended to and treated with some client centricity.