Moshe and Ahaaron come to Pharo saying that Hashem came to them and said that Bnei Yisrael to go to the dessert to bring Korbanot for 3 days. Pharo responded by asking who their gad was, and that he would not let them go.
After that conversation Pharo decided to increase the labor on Bnei Yisrael and told his officers not to give them the materials they needed to make bricks, and not to let them make less than they used to.
The officers were hard on Bnei Yisrael. They increased the back breaking labor, and told them they are required to build the same amount the used to while they still had thir materials.
The jewish officers came to pharo why are you increasing our labor and making us suppy our own materials and produce the same quota. Pharo respoded by saying he won't change anything.
The Jewish Officers returned from the throne room and approached Moshe and Aharon and told them that Hashem should atone them because they have caused Pharao to harshen his decree,like they gave him the sword to kill them.
Moshe came to Hshem and cried out asking why he chose to show himself to bnei yisrael, and why did he choose him. I wet to pharoa in your name, and I tried to save the nation but you didn't save me.