I didn't want to reply to you there because it is off-topic there.
Anyway, Hamas did not refuse anything. There is a siege since more than 2 years, but it was tightened since 6 months. The last truce agreement between Israel and palestinian resistants in Gaza including Hamas said:
1- No missiles from Gaza should be launched.
2- No attacks from Israel on Palestinians in Gaza.
3- Lifting the siege and allowing goods to enter Gaza strip and people to leave and enter Gaza freely.
The first two items were mostly applied, but the siege was never lifted. When the 6 months ended, Hamas was criticized in the Palestinian community because it could not lift the siege and everybody told it to end the truce unless the siege is ended.
You may see the siege as something immaterial but to know that no ill people could leave Gaza to be treated abroad causing tens of deaths, no students could leave or get in Gaza, no pilgrims to Saudi Arabia, no building tools are allowed to enter Gaza. Those are examples of the siege on Gaza.
So, the truce was ended because it was impossible to keep silent when people are dying in front of your eyes, and the coward world doesn't do anything.
Hamas decided to resume launching missiles into southern Israel to force Israel to lift the siege. Israel found it a good chance to make an invasion to Gaza and killed more than 1300 people. ANd I think you know the rest.
Just a question, what could Hamas do to end the siege?