Had plumber install new tub faucet (one piece) in fiberglass tub/shower. Center stem continues to leak behind wall after 3 additional trips back to my house to 'fix'. I discovered small hole coming from the fixture in the center - appears to be the bottom of the stem hole(plumber did not mention this). His staff said it can't be lowered. Wasn't aware this fixture wasn't same height as previous. Any solutions at this point besides buying
2nd new fixture? Plumber caulked it twice already.