Dear Mr Okafor,
I am writing to apologise sincerely for the delay in completing your new customer website, which we had promised to deliver by 30 June.
The delay was caused by a technical problem with the payment system that we installed. During final testing, we discovered that it was not processing some card transactions correctly. We could have launched on time, but I did not think it right to deliver something that might cost your customers money. We should, however, have told you earlier, and I regret that we did not.
Our developers have been working on the problem every day, and the system has now been rebuilt and is going through a second round of testing. I am pleased to confirm that the website will be completed and ready for you to use by Friday 12 July.
As an apology, we would like to offer you a ten per cent discount on the final invoice.
Yours sincerely,
Rachel Morgan