Investec Rejecting my Application for Home Loan with no valid justification

Investec has refused me Home loan with no valid reason. I have provided all relevant information to ensure my application is considered fairly and effectively, however my application is still rejected. I had a home loan with Investec which I paid off, during that period of my home loan, I have never missed a payment and ensured my credit record is clear with them. I also have my car finance with Investec similarly have never missed a payment. I am not under any administration or debt review process, I have no judgement under my name, and also my name is clear and not owing any institution. I think I am unfairly treated and this is not according to the national credit act. I would like fair treatment and valid justification on why my application is being rejected.