Debit order date not changed

Hi<br> I called Vodacom call center to ask for my debit order date to be changed, I cant remember the name of the call center agent that assisted me.<br> When I took the contract I was told my debit order will be on the last day of the month, but that is currently not happening. debit order goes through very late (7th or 8th) this month it has not gone through.<br> I called the call center last month to change my debit order date and I asked which dates are available for debit orders, then I selected the 21st as it was part of the available dates for debit orders and I was told it was changed, but debit order didn't go through on the 21st of May, even now 11 June debit order has not gone through.<br> Can this be sorted out please, I want my debit order to go through on the 21st