I have received good news from our insurance company. The customer service rep I spoke with was very helpful. She said that I would just need to write a letter explaining the medical necessity for the usage of the Mayo Clinic and it was almost sure to be approved. She is even checking to see if there is a way to get travel expenses to the clinic paid by the insurance.
I think the mistake was at the doctor's office or in the translation as English is a second language.
I am waiting now to hear as to what time frame in order get everything set up. My son has an interview with CA Technologies in Plano, TX on April 11th and would like to wait until that is done if it doesn't make a difference in recovery, etc.
Thanks for all the wonderful support.