Unauthorised debit order payment

On 12 February 2016, I called LGR Attorneys after receiving an sms that reads \Your African Bank Account was handed over to LGR Attorneys for legal collection. Reply YES or call 012 ***\", I spoke to Nomsa who confirmed that an arrangement can be made and we agreed that I will be paying R500 starting from 25 February 2016. LGR Attorneys sent me a number of reminders on 12,22, 23,24,25 Feb about the deduction and on 26 Feb 2016, LGR Attorneys confirmed receipt of payment. On 28 Feb 2016, African Bank sent me an sms telling me I had disputed their deduction. Today, 09 March 2016, a very rude lady named Wendy Mngoma from African Bank called to enquire about the dispute and I explained that it was because a deduction was already made by LGR Attorneys and she claimed African Bank had nothing to do with LGR Attorneys. So can someone tell me who authorised these deductions? and I need proof so I can take this further."