Originally Posted by OrangePower
There is only so much that you can do.
You can ask the bad caller "are you sure?"
You can ask the bad caller's partner "how did you see it?"
If bad caller is not sure, or bad caller's partner saw it in, then the point is yours.
Otherwise, you have to accept it, as frustrating as that might be.
Your only other recourse in unofficiated USTA league matches is to ask your captain to appoint a linesperson for the remainder of the match. The linesperson can be anyone who is there, but needs to be agreed to by both captains.
I have seen a lineperson requested on a couple of occassions but still it is quite rare. Things have to be pretty bad for that to happen.
Unfortunately, you are 100% correct.