WHY TWO DEBIT ORDERS AND DOUBLE THE INTEREST

Good day,<br> <br> I have a loan which I took out end November. I requested that for payment end December. I was asked whether I only wanted to pay the interest on 11 December 2015. I rep**** \yes"to the sms. My understanding was that once the interest was deducted the next debit order would only be end January 2015. However"