Hi Abby! No need to fear, your Jambox is not broken and can be easily repaired. Because your device will not turn on, this leads me to believe me that you have either a battery or charger problem. First, try your chargers again. Charging via MicroUSB should take 2.5 hours, and 5-6 hours via wall charger. Charging is taking longer, your charger may be the problem and you will need to purchase a new charger.
If you have found that your chargers are not the source of the problem, you will need to take out the current battery and replace it with a new one. iFixit has a very useful guide on how to do this, found on the Big Jambox troubleshooting guide under “Jambox not fully charging”.
Hope this help, good luck and have fun at the beach!