2 tax numbers old ***: new ***

I was employed in 2005 and I had a tax number, then currently I realised that on my payslip these another tax number. From the current tax number I was submitting my annual returns. So now I am garnished to submit returns on my old tax number and obliged to pay penalties. I went to SARS Polokwane, SARS Alberton and SARS Pretoria and still got no help. these matter has been going on from 2013 till date.