Do I need to submit tax return, back in 2013 if I earned well below the threshold?

I've recently submitted my 2015 tax return with Tax Tim. After phoning SARS - they mentioned that my 2013 tax return was outstanding. I only worked for three months of that financial year and accrued an income of WELL BELOW the threshold. Do I need to submit this tax return? Will I get penalized?

If you paid PAYE then you should receive a refund for that year. You can do your return via TaxTim as well. The 2015 filing season hasn't opened yet, but on 1 July you will be prompted to come back and push that final button.