paid account not reflecting

I pay the account monthly. I have been phoned regarding the \overdue\" account but I confirmed that I will pay today (15/04) whatever is due to me. I paid via EFT but I was told that it takes 2-3 days to reflect. I wanted to change from a 12 month to a 6 months plan, trying to minimize the costs. that cannot be done due to the \"outstanding\" arrears even if I can email the proof of payment. why was I not advised not to pay online if its delaying to reflect as I was denied to buy due to \"outstanding amount\" "