Moses and Aaron when to Pharaoh and spoke to Pharaoh the exact words God had given them. They were obedient and faithful to carry out God's instructions. But, instead of alleviating the suffering of the Israelites, it ended up only make things worse - much worse. It was hard enough to make the quota of bricks that was required. Now, it was impossible. When the foremen approached Pharaoh about the impossibility of what he had asked, he accused them of being lazy and having way too much time on their hands. Pharaoh's tactics were clearly to turn the people against Moses and Aaron, whom he saw as being nothing but trouble makers. His plan works, and the Foremen turn on Moses and Aaron with angry accusations. They are convinced this cannot be from God - because things have gotten worse not better.
This is a common theme all throughout Scripture - why does obedience and faithful service often end in troubles and increased suffering, instead of the promised blessing? From Job to Stephan and John the Apostle, lots of very faithful and godly people received far more grief for their efforts than comfort and blessing. We may encounter very similar experiences in our efforts to follow God and serve Him. Like the Israelites we may cry out - Why is this happening to me, and what can I do to avoid it? Doesn't God promise to protect and to take care of those who seek Him and follow Him? If God really loves us, why does He meet our efforts to serve Him with hardship and suffering? What is the point of following God, if we are better off NOT following Him?
This is a complex problem and there are many issues that could be discussed, but in the context of this passage there are two important truths that stand out. The first is that God has indeed promised to deliver Israel and bring them to the land of promise and blessing. But, He never promised that the path from bondage to blessing would be easy or without suffering and difficulty. The problem with the "prosperity Gospel" is not that they teach that God wants to bless all those who follow Him, the problem is that they assume the path to blessing can only be one of absolute comfort and ease of life! God promises ULTIMATE and FINAL blessing, but He also promises that the road to His final blessing will be one of struggle and hardship.
The Second principle, is that this is not about us - it is about God and His glory and reputation in heaven and earth. If the main concern was that of Israel's deliverance and blessing, then God could have affected that by means of a much more direct route. But, that was not His primary goal. His greater goal was to display to the World that He is infinitely more power than all the gods of Egypt combined. He was the supreme ruler who was Sovereign over Egypt and all the earth, not Pharaoh or the any of Egypt's gods. Because that was His greater purpose, the road to rescue would be a much more dramatic, albeit slower process!
If our greatest goal and desire is to see God's fame and glory increase and spread throughout the earth, then we will endure suffering and hardship with patience as a natural part of what God is doing in us and through us to make His name great. But, if our greatest desire and chief goal is our own safety and comfort in the world, then we can easily fall into the deception of serving God if it works out to our liking, but feel bitter and resentful toward God if our efforts to follow Him result in difficulty and hardship.