Modem replacement

I'm pissed.  Last Friday the Comcast tech showed up to replace our modem.  Prior to that happening we had three different options for wireless service.  Now the only option we have that works the public one that we provide for our customers for cell service.  There does appear to one additional option which is useless because I am unable to find a working password.  I run my business using the internet.  Now, nothing works as it did before.  Basically, nothing works.  I called "Customer Service" and was told the person I was speaking with was not knowledgable enough to work through our problem and that someone would be contacting me in the next 48 hours.I cannot afford to be unable to run my business for 48 hours.  I am sick to death of customer service people telling me "I understand your frustration and I am sorry".  That BS doesn't get me up and running.  Sadly, I don't have an alternative in our immediate area.  If I did I could get new service in here faster than Comcast can repair the damage they have done.