Reply in the language they wrote
A Hindi complaint answered in English reads as a brush-off.
Apologise once, then say what changed
“We’ve added one more person for weekends.” Then stop.
See the review page your customers would get
How it worksNever offer a refund in public
Google reads it as buying a better rating. So does the next reader.
The short version
Name the problem, name the fix, invite them back.