Money making schemes

What BS.... Is this that Vodacom Charges you R100 penalty fee on your account af the debit order didn't go through. But the very same day vodacom was phone and told the money is available they can debit from the account. Not there is suddenly a R100 penalty if a debit didn't go off. Where the hell do you get that amount. 1st time in my life something happens like that to me.