I saw you had answered this twice and no one had written anything, so I thought I'd have a go.

Basically Castro did everything wrong and Batista did everything right. Castro announced the date, giving the government time to prepare. During this time they stepped up the anti-Castro propaganda, issued threats to workers who would support the strike and placed the police and army on a war footing. The Unions were very much Batista's men and therefore the labour movement was, too.

Whilst the government knew, the people did not. People had no idea what they were doing or when. They were told about the strike and did not participate in choosing it, which robbed them of their autonomy and involvement, something that is typically crucial. The police and army were very well equipped ahead of time, whereas the M-26-7 rebels were poorly armed and unable to defend themselves. This meant that even if people had wanted to support the strike they were unable to take part due to the threat of terror.

There is some debate about the lack of support from other revolutionary groups. Some stories say that the M-26-7 group was over-confident and did not want support from anyone else. However, this is in contrast with what Castro usually preached - the unification of revolutionary groups. His March-12 manifesto specified various revolutionary organizations would have different roles.

(You can find some info here http://www.latinamericanstudies.org/cable/note-4-9-58.htm http://www.permanentrevolution.net/files/34-40%20Cuba_CORRECTED.pdf )