How is a bank not having the facility to reverse transaction or sent money?

How is a bank not having the facility to reverse transaction or sent money?

My mother sent money using the send money facility to a tyme that does not use a tymebank account. The person who was using the used number forgot to mention that they no longer use that number as that where they would have the money sent to in the past. After the money was sent my mom asked the person to confirm if they received the SMS with the voucher code, that is when that person said they no longer use that number for calls and SMS's but it is still active on WhatsApp. Within 30 minutes of the money being sent, my mother called your call center to stop or reverse the transaction as the money has not been withdrawn, she was then told she will have to wait 7 days and if this person has not withdrew the money then it will automatically reverse back into her account.

How does it make sense that a client cannot be assisted with such a small request, giving leeway for the person who is now using the number that the money was sent to time to go withdraw the money, A WHOLE 7 DAYS to get money that does not belong to them.

We have called the person and they deny receiving an SMS, help me make sense of your systems as this does not make sense at all!!!