If Condition Matches Multiple Times

I'm working on a problem that requires me to generator all possible word combinations based on a 7-digit number as input. Many of the generated "words" will be nonsense, but some with be "NEWCARS", "TAKEOUT", etc... This problem mimics the phone number a company would use to support clients remember that number.

I completed the exercise, but I would like to explore more elegant solutions. Specifically, I've used an IF-THEN-ELSE condition inside of a FOR loop. Here is my working code:

package com.johnny_v.exercises.telephone;
public class WordGenerator {
public static void main(String[] args) {
int numOfTimes = 2187;
String two = "ABC";
String three = "DEF";
String four = "GHI";

[code].....

I receive StringIndexOutOfBoundsException exceptions. I it's because multiple conditions are matched. For example, the indexSix is reset to 0 when row is a multiple of 9. Because row is also a multiple of 3, this condition also executes and then increments "indexSix".