When the enemy attacks us we feel our prayers are not being heard, that's when you should pick up the bible and start praying the psalms as your prayers with faith in God and the enemy will run away. I have practice that for years when I feel the same way, believe me the psalms can be used as prayers when we can't pray, but also brings us much peace and make our faith stronger as we get close to God in the process of reading them. Read them as if they were your cry to God and prayer.
Lord bless this person and help them in the battle they are having. Bring them your peace and strength to become victorious in you. In Jesus mighty name I pray amen.