It's very difficult to 'play' with guinea-pigs in the sense you can with a ferret, cat or dog, they're just not that type of animal.
They're better suited placed into a lovely large run or safe area of your house to run around in. If you have toys and tubes etc they can have to 'play' with and in, put those down for them instead as they likely won't play with you as such.
But it will take a very long time, and an immense amount of patience by you to 'tame' them. You just have to be slow, gentle and quiet around them if they're very nervous. You have to remember they are a prey animal and you're a predator to them, but they don't know you won't hurt them, as much as you love them, its one of those things you have to accept with guinea-pigs.
Hope that's put your mind at rest as it can be frustrating and upsetting to some owners not used to piggy ways.