Appalling Billing System

After receiving an email from Telkom asking to pay my internet for the month of May, I stupidly comp**** and paid via EFT on the 1st of June. On the 6th of June a debit order went trough for the original amount that I paid on the 1st of June and it resulted in a reversal. Now I am being penalized for a reversal on a debit order for an invoice that I've already paid. The logic beggars belief. Once again Telkom fails their customers.