请帮忙翻译一下，谢谢。语气要客气点，大意准确。

I have received the term of trade that you sent, but we did not sign or accept any regulation on penalty before. And of course, our company never sign or accept any penalty regulation with other customers. In this case, I hope that you can understand the reason why we did not accept as we do not wish that this kind of incident affect the relationship between your company and our company. We also know that you do support and purchase other products of our company such as xxx. We really appreciate this as your company is one of our parents.
Can you please inform me the person who in charged in purchasing xxx?

Hi xxx,

I have received your letter about the term of trade though we have not signed or accepted any relevant penalty of such terms and conditions.

I wish to let you know that our company have never involved in such terms and conditions with any organization before. In this case, we shall not accept this terms and conditions and hope taht such event wouldn't affect our business relationship. Hence, I hope you would understand our position and you have been supporting by purchasing of our goods/products ie. xxx with heartfelt thanks. By the way, we are glad to know that your organisation is one of our parent companies too.
May I know who is the person in charge of perchasing of xxx?