SQL - Group several lines in the same column with LIST TAG

select ost_pid_facility,
listagg(
  ('COL: '||trim(mic_txt_mis_value)||' OST: '||trim(ost_nme_alias)) ,
  ', '
)
WITHIN GROUP (ORDER BY ost_pid_facility DESC) "COL OST"
from vls_mis_code
inner join vls_fam_global1 on gb1_cde_code = mic_cde_mis_type
inner join vls_outstanding on ost_rid_outstandng = mic_pid_product_id
where mic_cde_mis_type = 'NGCOL' and mic_cde_prod_type = 'LOAN'
group by ost_pid_facility