Guinea pigs aren't shoes, you can't get a new pair when the pair you chose isn't 100% what you where expecting. They're more complex pets than most people think, they require effort, research, time and patience.
They're prey animals to pretty much everything else, so they're skittish by nature. They will run when you try to pick them up, all they see is a big scary thing coming towards them. They may never grow out of that either. The majority of pigs run from hands, even though they're fine and relaxed once you've got them. Ironically enough, the babies you considered replacing yours with would most likely be more squirmy and skittish than an older pair.
It sounds like you took these on very suddenly without doing much research before hand. Maybe you didn't get the chance to, I don't know, but you should certainly browse this forum in length, as well as CavySpirit, and GuineaLynx, so as you know what you're dealing with. They aren't the easy, no effort pet everyone assumes them to be.