Pliers. I can't see any other way. Those studs are absolutely vile, so I wouldn't be surprised if you end up having to get wire cutters and cut them out of your ears.
Unfortunately, this is exactly the sort of thing that happens when people are pierced by sub-standard shops. They mess up your ears using potentially dangerous piercing guns, then give you sub-standard jewellery that is faulty. Only to say that they're not insured to sort out the mess that they've created.
In future, have your piercings done by PROFESSIONALS who refuse to work with guns, but pierce in a sterile environment, with sterile needles. Learn from this!