and they BLASPHEMED the God of HEAVEN because of their PAINS and their SORES;
This is difficult for us to understand. We usually cry out to the Lord in time of great difficulty. Even unbelievers will request prayer in times of great distress. But these people do just the opposite. They BLASPHEME the very God of heaven who could RESCUE them.
This isn't just any god they BLASPHEME; this is the God of HEAVEN (the highest dwelling place of God, the place of His Throne (Revelation 4:2), His ark of Covenant (Revelation 11:19), and the altar (Revelation 16:7).
and THEY DID NOT REPENT of their DEEDS.
The DEEDS most specifically are referring to their BLASPHEMING God but may include other acts of irreverence. This is the last CHANCE, apparently, for these people to REPENT because the word "REPENT" is not used anymore in the Revelation text.
These people are at their valley of decision (Joel 3:9-14-15) and openly and verbally CHOOSE to follow the antiChrist. By this time, the conscience is very numb or nonexistent. Society has lost its moral code and only knows the PAINS and SORES they are suffering are because of these bowl judgments. Lest we think this isn't possible in America, there is an organization determined to get the 10 Commandments, a good set of moral codes, removed from public buildings. By this time, I can guarantee that the antiChrist has had every plaque or inscription that refers to GOD removed. How fitting that DARKNESS (previous verse), which is equivalent to the spiritual unenlightenment that these people have, be the judgment for this lost moral code.