VODAPHONE DEDUCTING OUT OF DATA BUNDLES FROM PREPAID AIRTIME

Once again Vodacom is deducting out of data bundles from my airtime. I received an sms from Vodacom this morning that R21.90 has been deducted this month to date. I have no contract with Vodacom. I am prepaid for airtime and buy data as when required. So why does Vodacom deduct out of data bundles? If I have no data then I do not have data until I purchase data. Welcome to Vodacom South Africa another dishonest company.