You needed to travel long to meet a customer. As you get there, they tell you the manager is sick and no one can replace him. How will you react?

Since you are already there, try to gather as more information about the prospective business, as possible, and fix a next appointment.

You must also call the customer to ensure his availability prior of starting the journey.

I would first provide my wishes for his early recovery,

Would like to befriend the company. Know more about what they do & their businesses.

Will try to get when the manager would be back & take one more appointment and visit him back again.

These happens on a routine basis,  i can't crib because he has fallen sick & thus consider it as part of my work & move on.

:-)

I would prefer to return back after handing over the visiting card and company profile; at the same time  I will visit the surrounding areas  and survey the possibilities for meeting new prospects. Often such instances tend to create new openings.  Even such instances can be utilized for visiting nearby customers to refresh the contacts and make use of it in a meaningful way depends upon the circumstances.