Would you please correct my grammar, thank you

Hi,

Please refer amount in our purchase order if you need to prepare the report in case the suppliers could not be sent us their invoice on or before 04 June which as explained to you previously/before that our invoices (date) were advance to meet the sales (forecast) as per Gigi request. Your level of English is not good enough to allow you to write such a long and complicated sentence successfully. You should rewrite it by breaking it into shorter sentences. This is what native speakers would do, to make the meaning clear.

I will try to push the suppliers to send it to us ASAP.

Best wishes, Clive