If ContactType is an enum, you need to convert the string value you read from console to corresponding enum value.
For example, if ContactType is defined like:
public enum ContactType
{
Home,
Office
}
And user enters "Home", then you need co convert "Home" (string) to ContactType.Home (Type/enum)
You can do this the following way:
ContactType contactType = (ContactType) Enum.Parse(typeof(ContactType), contactTypeString);