Customer Service is non-existent!!

I made an enquiry into interest charged for late payment, when I had paid over 16 days before the required 1st of the month, and I wanted a refund, because the payment was not late, simply early. I received a canned response saying I had paid late therefore I received interest. I enquired again (both enquiries I attached proof of payments) and yet again I received a canned response!

No one was even reading my emails!! This cannot continue, just because I pay my bill on payday at not on the 1st. I am getting penalised, and no-one at Woolworths is willing to take the time to read an emall.