pro-rata not explained

Good day<br> <br> On Monday 02 March 2015 i updated my details with one of the agents \\Angel\who assisted me with that and i added a rental vehicle option to my cover. i agreed to the new premium being R1300 and today i get an sms that Outrance debited my account an amount of R212.00 for what because no-one told me about pro-rata. <br> <br> You guys are getting to comfortable in taking peoples monies unauthorised\""