Do not straighten the door by hand
A crooked door may involve components that should not be handled while loaded. Do not pull on a cable, loosen a bracket or push a roller back into place. Keep people away from the opening and tell the provider whether the door is partly suspended.
Explain what happened beforehand
Mention any impact, unusual sound or recent work. State whether a vehicle is trapped or whether the opening is exposed. Those practical facts help plan the visit without assuming from a photograph that only one particular component requires replacement.
Review the cause as well as the correction
Ask what caused the uneven movement and which components were assessed. A proposal should explain why the recommended work is sufficient and whether other damage limits the options. Keep the written findings with the invoice if the system has a history of similar problems.
Your questions
Can I close it once to secure the garage?
Do not force an unstable or visibly displaced door through another cycle. Discuss the condition and access concern with the service provider.
Does crooked movement always mean a broken cable?
No single cause can be confirmed from that description alone. Report the symptom and let the professional assessment identify the affected parts.