First of all, it is spelled bonsai.
I suggest before you buy another bonsai, try to figure out what went wrong with the first one. Where were you keeping it? An olive tree is not a good choice for a beginner's bonsai.
Consider whether you want a tropical or temperate tree. The easiest temperate tree for beginners is Chinese elm, Ulmus parvifolia. Go to a reputable bonsai nursery. Do NOT buy one from anyone who tells you it is an indoor tree; it is not. You can easily find care instructions online. Start with Bonsai4me.com. You will keep it outdoors from spring to fall. In the winter you must keep it in a cool sheltered spot where it can go dormant.
The easiest indoor tree is a Ficus. Again, buy one from a reputable bonsai nursery, not a garden centre or supermarket. Keep it outdoors in full sun spring, summer, and fall. Most Ficus will be all right on a SUNNY windowsill for the winter. Under fluorescent lights is better. Contact your nearest bonsai club for more help.
Iris