Read this section of a letter from a customer to Raj Kahn. What is the main purpose of the letter? Choose from A to C. Dear Mr. Kahn, I am writing to complain about our stationery order of 12th March. Following my telephone conversation to your office on 21st March, I expected to receive the correct goods. However, that was a week ago and we are still waiting for delivery. Could you please assure me that the order will be sent correctly and as soon as possible? If not, we will be forced to look for another supplier in the future. Yours Sincerely, Peter Paxman