Double deductions

The way I was so excited to use the app I even convinced my husband and friends to use it as well little did I know that the one person who was convincing people to use the app is the one who is going to be ********** ,I started using the App on the 3rd of September I bought something at cape union mart paid the 1st instalment then to my surprise the money was taken again on the 5th why deduct money when I was nowhere any shop and I didn't authorize it please pay back my money I have sent an email with my bank statement showing the amount taken.