Please accept my most cordial thanks for your timely help, which I will never forget.

请接受我诚挚的谢意，感谢你及时的帮助，我将难以忘怀。

youdao

Please accept my sincere thanks for your help, which I will never forget.

请接受我真诚的感谢，我将永远不会忘记你的帮助。

youdao

I will never forget your kindness. If you are in need of help next time, I will show up to give you a hand.

我不会忘记你为我所做的一切，下回当你需要帮忙的时刻，我一定会出来助你一臂之力。

youdao