Summary: Seems like everyone is having problems with chipmunks including me. There are numerous methods for detering chipmunks, some better than others.
In your chipmunk control efforts I can tell you that mothballs definitely do not work. They may make the chipmunks relocate, but they do not rid your property of the animal. Animal repellents like Ro-pel require multiple applications and usually don't provide the results you desire.
There was a good chipmunk bait, but the EPA has changed the rules and forced the manufacturer to remove the product from the market. So what's left? Hopefully this article will give you some ideas.
Rodent snap traps are inexpensive and can be effective if you bait them properly and place them in the path where chipmunks frequent. You'll need to put something attractive on the trigger of the trap such as fresh peanut butter. I like the standard Victor snap traps, but you can also use the easy-to-set Trapper Mini-Rex traps.
Live traps made by various manufacturers are expensive, but you can purchase multi-catch repeater trapsthat can capture eight or more chipmunks per setting. The live trap will work, but you must pre-bait before setting the trap to capture the animals. Pre-baiting a trap allows the chipmunks to become accustomed to entering the trap without harm. The chipmunks disassociate the trap with what is causing them to be captured. "Hey! I've been in and out of here lots of times to get food. Why an I stuck in here now?" Allow chipmunks to enter and leave the trap for several days. Then, set the trap and see how many you catch. Once caught them you must not release them or they will return.
I have read about a method that a lot of people seem to like. Take a five gallon bucket and fill it halfway with water. Sprinkle a layer of sunflower seeds on the surface of the water. Put a 1x4 wooden plank across the top of the bucket and sprinkle some seeds on the board. The chipmunks jump up on the board to get the seeds, then jump into the bucket to go after the floating sunflower seeds. I have read you can catch numerous chipmunks in a single evening.
There are also battery powered electronic rodent trap zappers that kill small rodents when they enter the trap. These are not inexpensive, but they do work.
I'm buying a bag of sunflower seeds and doing the five gallon bucket method.