请大家帮我翻译下下面这段话 ，用英语，不要机器，可以让客户明白意思。我是做油画的。

Question

（客人的画到达他们公司，产生了额外的关税费用，只有他们交了关税的费用才能拿到画）
亲爱的朋友：
我们已经和快递公司联系了，TNT不是要多收两次费用，而是画到达贵国的时候产生了额外关税费用，TNT公司已经帮你们把关税交了，所以他们要收取您关税的费用。

Answer 1

Dear Sir or Madam,(商贸函电开头若不知道对方名字一般都是这样，没有说亲爱的朋友的)
We have connected with TNT Express and get their explaination: it is not the TNT Express wants to be paid twice. When the cargo reached your place, some additional custom fees generated and TNT Express had paid it for you. So they need to charge the custom fees for the cargo.

尽我最大努力翻译了，虽然翻译不是很好，但个人感觉楼主客户看懂没有任何问题，绝非软件翻译，祝生意兴隆。

Answer 2

(Since the customer's oil paintings generated extra customs fees and charges, only when they paid for the fees can they get the oil paintings.)

Dear friends:
We had communicated with the express company. We learned that TNT was not charging your fees twice,it was because extra extra customs fees and charges were generated when the paintings reached your country.TNT paid the fees for you in advance, therefore,you need to repay TNT.

Answer 3

这个是外贸的，呵呵。等待外贸达人吧

Answer 4

Dear Sir or Madam,
We have contacted with TNT Express Agency,and the fee they charge from you is the additional tariff they have paid for you when the painting reached your country,but not the money for the pating again.