DUO allows you Unlimited Calling to and from any landline number as well as Unlimited Calling to and from any DUO postpaid mobile subscriber

how does one avail of this duo?

txt DUO<space>MM<space>ON and send to 8888...

kala ko 399/month..? tma ba.?

yup... 399/month, on top of your MSF and for postpaid subs, there is a 3months lock up period..

if you choose to unsubscribe before the 3rd month, there is a 1200 preterm fee