Mon "While" fausse le résultat de mon calcul

#include <iostream>

using namespace std;

int main()
{
    double x, y;
    double total = 0;
    char op;
    cout<<"Enter your first number: ";
    cin>>x;
    cout<<"Enter your second number: ";
    cin>>y;
    cout<<"Enter an operator: ";
    cin>>op;
    
    switch(op){
        
        case '+':
            total = x+y;
            break;
            
        case '-':
            total = x-y;
            break;
            
        case '*':
            total = x*y;
            break;
    }
    
    while((op != '+') || (op != '-') || (op != '*')){
        cout<<"Bad operator. Enter en operator: "<<endl;
        cin>>choix;
    }
    
    cout<<"Total:"<<total<<endl;
    return 0;
}