请帮我翻译成英文，不要机译，谢谢

Question

我已经收到了这两笔付款， 第一笔RMBXXXX的发票已经在三月底开出，并在4月与XXX的合同一起寄给您啦。几日后，我收到了贵处改好公章返回的合同，所以没有继续跟进发票的事。附件里是我当时开发票的底单，以及当时与发票一起寄给贵处合同的首页。如果有任何问题，请再联系我。由于近期发票系统升级，所以可能要在月底才能开除第二笔金额的发票。请您不用担心，如果发票开出，我会及时联系您。

Answer 1

i had received the two set payments, the invoice of first RMB XXXX had been issued in the end of March, it had been sent to u by express combined with contract XXX in April.
Several days later, i received the signed back contract, in that case, i did not follow up the invoice cases. Encolsed with the filed invoice page and contract first page sent together. If there is any question, please contact me freely. Due to the update of invoice system, so the invoice of second payment will be issuced in the end of this month. Do not worry, once the invoice came out, we will contact u in time. 翻译完才发现好业余，唉，将就着看吧。 实在不好意思说自己是专八的，可悲的匿了。

Answer 2

I have recieved two of your payments, one is XXXX RMB and the invoice of which shall be issued at the very end of March and send to you by courier together with the XXX contract in April.

a few days later, i got the feedback contract with your company seal and didn't follow up the invoice details. Attched here is the invoice duplicate and cover page of the contract that had been sent to you with the invoice.
Please check gainst those details. If you still get doubts, please feel free to contact me.
By the way, the invoice for the second payment shall be issued at the end of the month due to the invoice system's upgrading at the moment.
Please do not concern it too much, i will contact you as soon as the invoice is issued.