I am having a wire problem with my hot tub. Had hot tub tech come and he said the problem is in the wiring from the house to the sub panel. He said that the Red to White is reading 120, but the Black to White is only 60. Together the Red to Black is only 180 and we need 240. What could be the problem? I hired an electrician to run the wires and hook up the hot tub he was supposed to come back to fix what was wrong (thinking it was a bad GFI) but now he will not get back to me. I can not afford another electrician. Is this something my husband and I can figure out and fix ourselves? Being the problem is from the circuit box inside to the sub panel outside where would I look for the problem and how do I fix it? Thanks!

This is straight up troubleshooting. Unless you are pretty well versed in electrical work and troubleshooting I'd hire another guy.
How long ago was the circuit run? Was it ever working right?
If not long ago, as in a few weeks, I'd call the old guy back and tell him you are going to hire someone else and send him the bill.

When you get odd voltages it is 9 times out of 10 a neutral problem.