Corporate Contact Information -- Modem Broke, Taking Forever to Fix, losing business

I own a dog daycare. Yesterday, my modem just broke. I called customer support and did all of the troubleshooting with them and they confirmed the modem broke. The soonest a technician could be scheduled to come out was the next evening--so over 30 hours of not having internet. That is unacceptable, as the business needs internet to function. My phones are down and my credit card reader doesn't currently work. It is a busy time for us right now, as people are trying to find boarding for their dogs for Spring Break these next couple of weeks. This issue has caused financial harm to my business as I'm sure people who have called trying to book a reservation have simply moved on to the next option. Not only am I losing that customer for this week but that could be a lifelong customer that I am losing as well. Not only the financial harm, but my business reputation as well, as current customers aren't able to call and check on their dogs which makes it seem like we are not giving their dogs the utmost care and respect. I was told "not to worry about it" by multiple customer service representatives and someone would come as fast as possible. I know it is not the representatives fault as they have limited power in what they can do. I am looking for some sort of corporate contact information in order to expedite the issue and get some help because this is ridiculous. I am revenue. Also, when I tried to get some sort of credit to my account to account for the lost business/revenue this issue will cause me, I was told the only credit I will receive is not being charged for services while the internet is down--which will amount to $10 probably. It is crazy that we have to pay for a service when it works but when it breaks, they are not responsible for anything that comes from THEIR product breaking and THEIR lack of response to that issue.