Incorrect debit order date

My agreed debit order date with Blue security is the 25th of every month. In January 2015 my bank account was debited on the 23rd and this was communicated to Blue security, some lady called me from Blue assuring me that I will not be charge an unpaid fee of R40 of which it didn't materialized and incurred R115 unpaid fees my my bank since there were not sufficient funds. Again April 2015, my account debited 24/04/2015 incurred another R115 unpaid fee.