I had a job where that happened, but I was fortunate enough that they called me before I left to head to them. (It was a long drive.)

Every morning they called to say "I'm sorry, we haven't been able to get your account setup yet. Can you come in tomorrow instead?"

That lasted for a week. The last day I didn't even bother to get ready because I figured they'd be doing the same thing and just starting me the next Monday. It was a risk but it all worked out.