a matter of complaint的用法和样例：
- As a matter of fact, I've never been there before.
- As a matter of customer service, the redressal of complaint should be in place without any loss of time.
- It is a matter of life and death for them.
- It may be a matter of months before it's ready.
- The revolt was suppressed in a matter of hours.
- Is success simply a matter of working hard?