Born after 1985? Call will be fine. Quick, polite, and understanding that you are not the company. Not demanding or rude about things.
1985-1965? 50/50. Good chance of getting yelling and anger. But usually not directed at you personally.
Born 1965-1945? May God have mercy on your soul. Holy s*** the amount of entitlement, and condescention from this group was insane. No concept that the person on the phone doesn't make or have any control over company policy. Will not admit to any ignorance.
Born before 1945? Call will be fine. Person will be very nice, but possibly confused and need extra explanation. Will generally tell you when they don't know somthing. Will talk to you forever, best small talk.