怎样才能劝客户改用T/T付款？

Thank you for you reply. Please excuse my late reply to your very friendly letter of yesterday. Sorry to have kept you waiting. Please accept our thanks in advance for your usual kind attention.
I am very regret to tell you that my boss doesn't agree on L/C. Firstly, we will have more troublesome if we use L/C than that of T/T. We always do business with T/T, we are not very familiar with L/C. Secondly, the charges of L/C is very high, a lot of money will be wasted. It's not good for you. Lastly, our factory doesn't agree on L/C, either. Our factory cannot work on with L/C as the quantity of tyres is large. So, could you please consider with T/T? It is easy to operate and cost little. If you are worried about the quality of oue tyre, I can send you several samples for you to check out.
Kindly excuse me for troubling you in this matter. We spare no efforts in endeavoring to be of service to you. We solicit a continuance of your confidence and support.