Did you see that heater in the pics tho? It obviously exploded. And yes, corners are almost always the strongest points. Don't lie about anything, don't move anything. Report everything as you know it and you should be properly reimbursed. I would send them a link to this thread too, so they can see it's honest, and that others are having problems with their products and if they don't do right by the customers, their business will suffer. This site carries a lot of weight with fish hobbyists with thousands reading daily. Not properly taking care of business on their behalf, will only hurt them.
Don't let this get you out of the hobby or discourage you in any way. Come back bigger and better.