Tonno Pro Hard Fold fittment?

Hey guys. So I bought the Tonno Pro hard fold for my '12 CM. I read a lot of reviews and they were 90% 5 starts. For the price it is hard to beat for a 350lb resistant hard fold, plus i like the vinyl cover that makes it look like one piece. Issue is That when I installed it (very easy just clamps under bed unfold and then clamps at end of bed by tailgate) it did not lay flat at all. I thought maybe need to give it time to settle, but it was bowed and never layed flat at tailgate. It always seems as though there was tension and the end by the tailgate wanted to come up. I took pictures and sent to Tonno Pro and they were all very nice about it and said it was a defect and the top was over sewn so they would send me a new one. That was great! But I have put the new one on and while it is better there is still a couple (2) centimeter gap between top of tailgate and cover. Has anyone else got this cover or have a trick. I like the look but want it to lay flat and function. Thanks. i'll add pics once the dealership gives me my baby back.