Debit Order date incorrect_Unpaid Charge

On the morning of the 20th, I get an unpaid item on my bank statement. What changed? The agreed date is the 20th...<br> <br> After spending 22 months with Telkom mobile as a loyal customer,now legible for an upgrade, suddenly my account gets debited on the 19th June 2015 which fell on a Friday. My initial agreement was the debit to go off on the 20th of each month. Called and spoke to Sihle (Call Centre Manager) who advised me that Telkom does not debit on a Sartuday and/or Sunday but would rather debit the day before Saturday or day after Sunday. I was never advised about this when I signed up for the contract. Nonetheless, it is not the first time we have the 20th on a Saturday however it is the first time I am having this issue. In 2014, we had the 20th on Saturday in Sep and Dec.<br> <br> A lot of contradictions and failing to admit to an error, I find myself with a negative record on my bank statement and a charge of an Unpaid item while I'm in a process of buying property. While at it, my loyalty has proved nothing to Telkom, and I ask myself if they will rectify this issue:<br> <br> Delete the unpaid item on my bank statement<br> Refund my unpaid charge<br> Refrain from debiting on an incorrect date<br>