Complaint letter from a business customer to a telephone company

Dear Sir,
I am writing this letter to complain in the strongest terms about the poor service that I have received from your company.
We signed up to your telephone and internet service package two
months ago because your advertising suggests that you are better than
Telco. In addition, you promise to deal with problems quickly and
efficiently, something that Telco were unable or unwilling to do.
However, in the first month of service you managed to cause me to lose
two days worth of business because of poor administration. The main
problem was that you failed to provide me with the correct telephone
number, 9818 8747, that you had promised when I completed the contract.
This phone number was an established business line which I had been
using for the last three years. Obviously this meant that my clients
were unable to contact me and it cost me many hours of phone calls to
resolve the matter with your support centre.
I would appreciate it if this situation could be resolved and a substantial rebate offered on my first three month’s account.
I look forward to hearing from you soon.
Yours Faithfully
anggun matheos