Abused by ABSA

As a customer of more than 15 years with absa I'm very disappointed in their service, I feel ****med by the bank that I trusted since my childhood. Absa is billing me twice for a property of over 300k. One debit is the installment which I'm aware of and the other they call it interest, which is the same amount as the installment, ABSA is looting my account and I'm very angry 😡, I just want them to refund my money, before move to another bank.