Developer refuses to hand over documents

Well, I consider this below average for standard construction practice; if I were the actual builder and not just the buyer, the creators of this work would have to at least redo the defective parts once. As far as integration is concerned, I don't want to say much; if enough masonry anchors are used, no bond is necessary. Then it can be fine. As a BT customer, meaning buyer, only the final result has to meet the standard and ordered specifications.

My stomach is turning... and yet I'm the one here who always keeps a low profile.

As a BT customer, i.e. buyer, only the final result of the standard and ordered execution must comply.

And that is exactly where our problem lies. At the final acceptance, nothing of that is visible anymore, but we JUST KNOW how terrible the walls underneath look. And yet we have no recourse? Do only the defects visible at the time of acceptance really count?

terrible how the walls underneath look.

Looking terrible does not mean you are getting a defective house.

"Terrible" in quotation marks, referring to the grievances or substandard work mentioned a few posts earlier.

We have now been able to identify blatant defects in the construction of the interior walls; in some cases, the required bricks were "cut" with an axe instead of using the available saw. The walls look accordingly,

As seen, somewhat arbitrary and in some eyes catastrophic...

A complaint to the developer has so far led to nothing, it was ignored.

... but not a defect if it is plastered properly. Whether developer or general contractor...