plumbing problem

its been months, and I still have problems with my sink. The plumber visited my place so many times and tried to fix it, but still he cannot do anything about it. It keeps on leaking. I been constantly visiting the store to buy what I need but I cannot find the way to fix the darn kitchen. You just have to find the best plumbing fixtures to make sure that everthing in the will be done just like what you wanted, from the faucet in your kitchen, bathroom, sinks and shower room.