olives

I like olives very much. Do you know those olives that come in squareish plastic boxes with a thermally-sealed plastic film cover? I think I've gone through three or four brands and all of them have the same flaw. The plastic film is thermally sealed around the box edges, but on one or two corners the seal is moved inwards to allow you to pull the film upwards and open the box. I couldn't open a single box using this suggested method. All of them had their cover cut with a sharp knife. This is stupid. Why the hell do they provide opening tabs on the corners if the film is so tightly sealed it simply won't come off? One time I used a set of lineman's pliers to pull on the tab and it still didn't break the seal, it did however tear the tab. Piss-poor design.