Query of owe SARS

Kindly be advised that I'm worried about I owed SARS Tax.what I worrying about is are every year I will owe SARS? There's deductions on my payslip of R1500,00 and which means they will deduct they until XSARS-SARS PENAL is finished. Why I must owe SARS cause is them who made the deductions every day?I joined the company like Sanlam,old mutual, Platinum life, Metropolitan Sizwe Madical Scheme law for all,ect and I have the certificate of that.please find out more about why I owe SARS?