Is this a widespread faucet? What was the name brand of the faucet? Do you still have the instructions? It sounds like you may have installed some parts wrong. I would look through the instructions in the box and try and figure out what is going on. But David is right, most of the time on the newer faucets the cartridges can be reversed. In addition if its a Delta (or equivalent) you may simply be able to lift the cartridge and rotate it 180 degrees and reinstall it and solve your problem.