I have had this problem with sound guys on a few occasions. what does "make sure they pad it down' mean?
Number one rule- MAKE SURE THE FOH CHANNEL YOU ARE IN IS SET UP FOR LINE LEVEL. If not make sure they pad it down. You may want to snag a direct box to carry yourself in case the venue can't handle line level.
If you barely have the level out up and the sound guy keeps yelling at you to turn down, he doesn't have you set right (and most likely doesn't know what the fuck he's doing). BE SURE to correct this fast and don't let him bully ya into believing it's your unit.
Had this happen to me twice- even told the sound guy(s) REPEATEDLY to pad me, they just couldn't wrap their heads around it. Had to step out to FOH & do it myself. Then they look at you and go "ooooohhhhhhh".