Debit order processed 5 days early

I took out a policy with Outsurance this week and was told my debit order would run on the 20th. I was told about the pro-rata insurance premium but assumed this would go through together with my regular debit order on the 20th. <br> <br> However it was processed through my account last night resulting in me being overdrawn. My bank will now debit me with an excess fee of R57 and I will not be credited with a debit interest rebate of around R170 due to Outsurance debiting my account too early. Further to this I found out after taking out this policy that I would enjoy a 10% discount as I am a FirstRand employee. I was not advised of this either.