Out of principle, I feel I should not have to fix or alter or modify something new out of the box in order for that something to perform as intended new out of the box. After all, the money I paid for those something's did not need to be fixed or altered or modified to perform as intended. If consumers continue to accept/buy crap, manufactures will continue to manufacture/sell crap. I chose to be part of the solution rather than be part of the problem.
Anyway, today I loaded up both tanks and my tools to check for warped glass and visited Petco. I walked into the store with my receipt in hand and ask to see the store manager. I explained the situation regarding the poor quality of the materials Tetra used to construct my tanks. The first words from the store manager were "would you like to exchange both or refund for both?". No hassle, no silly questions, no nothing except a willingness to help me resolve the situation. My response was that I would exchange only if I can thoroughly inspect the tanks to be exchanged.
The manager called the supervisor of the fish/aquarium section and explained what was going on and what was about to happen. Both of them were eager to help and total pro's in there actions and words. I retrieved my tools from my truck while they located the 40B's, since the sale was over, the 40B's were moved back into the warehouse.
We went over seven tanks before we found two that were flat. It was a mixed bag of results, some were concave and some were convex. They were very surprised to see the undeniable errors in the materials before their very eyes.
They loaded both flat tanks on a dolly, wheeled them to the register, I completed the paperwork for the exchange, they wheeled them to my truck, I unloaded the warped tanks and they loaded the flat tanks. Throughout the whole ordeal, they apologized repeatedly for the inconvenience. Out of curiosity, they checked my warped tanks with my tools and were again surprised to see the tanks I exchanged were worse than anything we checked in the store warehouse. One of them said "no wonder you brought these things back!"
At this point, I'm could not be more happy with Petco and how they handled the situation. Like I said in my comments above, total pro's in their actions and words.
Caveat emptor!