对此我十分抱歉。
Im very sorry about that.
我对此感到十分抱歉,希望您能尽快收到。 有任何疑问,请告诉我。
If there's anything I can help with, don't hesitate to tell me.
本人汉语水平与各位的英语水平相比实在是相形见绌,对此我十分抱歉。 但我仍然十分期待与各位进行此次对话。
And I am very sorry that my Chinese is not as good as your English, but I am looking forward to this chance to have a dialogue。
希望能对你有帮助,记得采纳我的答案哦!!!