Arduino - Serial Communication not working - c

Question

I'm having problem getting in to the second Serial.available loop of my code located in the Package. Please, let me know, if you see anything wrong with the code.
Arduino Code
Inputs:
1. "Package" -> I get +1 back from the Serial Monitor
2. "5&12!23!34!59!70!" -> I get 0 back from the Serial Monitor. For this one, I'm supposed to see, 5 12 23 34 59 70
Please, let me know, if you see anything wrong in this code and why is the Serial.available not functional in the Package?
String incoming;
String readIncoming;
int i=0;
typedef struct {
int npins;
int addr[512];
}
measureList;
measureList list;
void setup() {
Serial.begin(9600);
Serial.println("Serial conection started");
incoming = ""; list.npins = 6;
}
void loop() {
while(Serial.available() > 0) {
incoming = Serial.readString();
if(incoming == "HI") { Serial.println("Steven"); }
if(incoming == "SampleAll") { SampleAll(); }
if(incoming == "Package") { Serial.println("+1"); Package(); }
}
}
void Package(void)
{
while(1)
{
if(Serial.available()>0 & i<= list.npins)
{
char recieved = Serial.read();
if (recieved != '&' & i == 0){incoming = incoming + recieved;}
if (recieved == '&' & i == 0){list.npins = incoming.toInt(); Serial.println(list.npins); incoming=""; i = 1;}
if (recieved != '!' & recieved != '&' & i > 0){incoming = incoming + recieved; }
if (recieved == '!' & recieved != '&' & i > 0){ list.addr[i] = incoming.toInt(); Serial.println(list.addr[i]);incoming = ""; i = i + 1;}
if (i == list.npins) {break;}
}
}
}