Apology Letter For Inconvenience

Dear [Mr. X],

Allow me to express my sincere apologies for the unintentional mistake and the inconvenience caused thereafter. This situation is certainly unusual and we are annoyed about this as much as you are.

As per my findings, this error occurred due to [state the reasons here. Make it short]. This is clearly a mistake at our end and we take responsibility for it.

In line with our commitment to the satisfaction of our customers, we decided to [give you a new item, refund your money, etc…]. This is the least that we can do given the current circumstances.

You should also know that we are in the process of implementing additional safeguards to eliminate these errors in the future.

I apologize again for the inconvenience.

Best Regards