No IRP515 = no tax refund

I was overseas studying for tax years 2010 and 2011 and therefore didn't have IRP5s for those tax years. However, I did have income in the form of rental income but for both years I made massive losses due to expenses, high interest rates, bad debts etc. Does the lack of IRP5 automatically disqualify me from any refund due to me by SARS?

No it does not, you would only include the rental income/losses under the Local Business Income section of the tax return or on TaxTim under Business/Rental Income. However due to you probably not have paid any tax throughout the year there would be nothing to refund, but rather you would be paying in.