there should be some instructions or a number to call or write to on the letter??..
If not I think the wc adjuster sets up the appts so you need to go thru them- don't contact the qme doc.

I'd just say you have plans to see your family and you will be out of town at that time.. none of their business about the beach part...
Wouldn't want them thinking you are vacationing and having a little bit of fun or something
fun isn't allowed