Debit Order deducted without written concent

I received a Mail from my Bank that a Debit order of R299 went off my Cheque account and after investigating this matter Absa Digicash name popped up.Then i contacted them and were told they are contracted to collect money for other companies that i have a sighned contract with.Firstly i have never sighned any contract with that Company for any Debit order and Secondly any Big company like ABSA should ask for a Written Proof where i sighned before they consider loading that debit order,otherwise its ***** and legaly wrong to take money of anybodies account without their written concent.Then i was told to contact the ********** to correct the matter.The money was taken off my account not by the Company but by Absa Digicash!!! WITHOUT PROOF OF WRITTEN CONTRACT!!!