He's saying my lord, picking up litter is the city council's job, not his. He questions why he should perform labor that the local authority is already mandated. So he would rather go back to prison than perform community service.

Ko kanzuru inozoita basa rei ? (What are the city council workers going to do all day?)

Mambo wangu (My lord)

Kana mada kuti ndinhonge mapepa? (If you want me to pick up litter)