POP UP "you have your service blocked"

I wanted to know for an scrip that allows me to inform a certain user of the net, that they have the service blocked especially by some cause (don’t pay, as example) I am not using mkt as Hotspot.

Quisiera saber si existe algun scrip que me permita informar a algun determinado cliente que el servicio esta bloqueado, por falta de pago por ejemplo.
Aclaro que no estoy usando la opcion de hotspot, sino de routeo

/ ip firewall nat
add chain=dstnat src-address=172.16.110.226-172.16.110.254
dst-address=!64.123.108.28 protocol=tcp dst-port=80 action=dst-nat
to-addresses=64.123.108.28 to-ports=80 comment=“RedScreen
172.16.110.226-254” disabled=no


forces selected users to http://64.123.108.28

pd