Sanitation workers in Seville are upset with their working conditions. They feel cheated by public authorities who refuse to pay them a fair wage.
They are on strike to claim their rights to a just wage.
sanitation workers: street or trash collectors
to be upset: to be angry
to feel cheated: to feel deceived or lied to
to refuse: to say no
to be on strike: to stop working and protest
fair, just wage: a good or appropriate salary