Unauthorized debit from my bank account

Once again in just a space of 5 months Digicash has made another unauthorized debit of R99.99 BOSSRWDS 20D5571BR 151221NAEDO DR *** from my bank account . The last time they did the same thing ( Phantom 3BAWV Digicash150625naedo )and gave me the useless email and number for their client who supposedly gave them my banking details . I'm starting to get tired of this nonsense from Digicash.