。
The parents had no choice but to scold the child.
Literal
Parents [topic-は] child [object-を] not-scold [can't-avoid-わけにはいかなかった].
~ないわけにはいかない is a double-negative obligation: 'can't not do X' = 'have no choice but to do X.' More nuanced than ~なければならない — it implies external circumstances forced the action rather than a general rule. Past tense いかなかった places the obligation in the past.