Unfair late payment billing

<p>I want to know why there is a late payment charge on every bill I get from telkom. Since the start of my contract with telkom in 2011 my payment date has never changed. My salary date is the last day of the month and has been since 2011 but I get charged every month for not paying my bill on the 25th of the month. I want to know what the problem is here because I am penalized for no reason.</p>