sqlplus spool to CSV file with headers truncate column names, other issues

I am trying to run sqlplus from UNIX script to create csv file output with headers

I can generate the csv output, but when column names in headers look truncated or missing or damaged.

I use "select * form table" statement because the table has a lot of columns, and there are a lot of tables to produce output from, so to individually list all columns in the "select from dual" statement would take too much work (hundreds or thousands column names to code).

So I tried to simplify the code by using set colsep "," but it produces many wrong column names.

Do you know how to fix it?

Another question is how to surround string outputs with "" to prevent embedded commas to break the CSV file layout.

This is my code:
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#!/bin/sh
#echo "Trying to connect to sqlplus..."
sqlplus -s /nolog > /dev/null 2>&1 << EOF
connect user/password@database

set echo off
set feedback off
set linesize 1000
set pagesize 5000
set newpage 0
set colsep ","
set term off
set verify off
set heading
rem set headsep ","
set trim on
set trimspool on
set underline off
set wrap on


spool /usr/lawson/auditrpt.tmp

select * from MYTABLE where OPERATOR='username';

spool off


quit
EOF
exit

_______________________________________

First few columns of the table should look like this:
VENDOR-GROUP,VENDOR,VEN-CLASS,VENDOR-VNAME,VENDOR-SNAME,VENDOR-CONTCT,REMIT-TO-CODE,PURCH-FR-LOC,PAY-VENDOR,VENDOR-STATUS,VEN-PRIORITY, etc.

However, in the file they look like this:
VEND,VENDOR   ,VEN,VENDOR_VNAME                  ,VENDOR_SNAME                  ,VENDOR_CONTCT                 ,REMI,PURC,PAY_VENDO,V,VEN_PRIORITY, etc.

As you can see, some column names are displayed properly, and some are not.
The data output seems correct though.

Please assist.
Thank you in advance.