Unknown credit Account

This peoples are calling me about the a count that i dont know and after several calls from them i have been asking them to send the proof of what they claim I'm owing from Absa and when I was handed over but these no answer about that and now they are saying exte. We are proceeding with legal steps and when i enquire from Absa branch and transunion these no records of what they want from me. MBDINC today on (011) ********** regarding ur acquired ABSA acc. Ref: ********** ********** 09