If you have received a grievance from someone, here is a sample template you can use to write a letter acknowledging a grievance.
To [Recipient name]
Dear, [Recipient name]
This letter is to acknowledge receipt for your grievance letter sent to [Name] dated [Date]. We are committed to offering high-quality service and we will look into your complaint with careful consideration. We regret that you have issues and are willing to hear your case to make a fair judgment.
I invite you to a meeting held on [Date] at [Time] where you will be given the opportunity to state your case and provide the details of your issues. You have the right to be accompanied by a colleague or trade union representative. You can feel free to contact me for any further clarifications at [Number].