ABSA: No due diligence before approving home loan

I recently signed an offer to purchase thinking that all of the banks would require plans for the house as well as a certificate of occupancy. That was the case, except for ABSA. They approved a loan for the place without requesting any documentation. Now it has come to light that the house was built without plans and I have my doubts about whether it complies with the building regulations. But I have to buy the place because ABSA (and only ABSA) approved the loan. I might be forced to demolish the place before I finish paying off the loan, but ABSA still approved the loan. I'm phoning the building inspector on Monday. Hopefully he goes to look at the place before I am forced into buying the property.