UPS SARS None-Compliant

It's heartening to have to resort to this platform as I see no other way out. I am in debt with SARS because my former Employer did not comply in the years I was employed. I was employed by UPS 2***, during that period my Company did not pay my Contributions to SARS but it reflected on my payslips. This year SARS made me aware that I owe them and made it clear how I owe them, a huge amount of money, and that amount didn't make sense since I thought I have been compliant all along. I went to find out from SARS as to how I got to owe them that money. I was advised that during the period of my employment with UPS which is from 2019 March till 2020 February there were NO Tax submissions paid from my side. I than took it to UPS to get clarity as to how that has happened. I was advised I needed to send HR an email stating my case which I did. I had to follow up twice more until I had to call to find out what was going on, I was told that it cannot be a fault on their end that I might have had an extra Source of income during that time. I then emailed and requested an Irp5 and the proof of employment which I only received the proof of employment. I went back to SARS with the documents they than confirmed that I was indeed with UPS and that they were only my Source of income then. I went back to UPS and I'm NEVER getting any tengible information on why SARS was not paid during that period. I am Frustrated and I don't know what to do from here and I'm about to be Gunished by SARS!!!