Sentence 1: You wanted me to adjust the sales figures by considering official ratios which wasere published by the government.

The ratios in September and in December are different.

If you apply the same ration in September to the cancelled sales in December, the net effect would be zero.

But in this time, the P&L statement in Cthe corporate Ttax Rreturn will be more different than the one I submitted to you.

Sentence 2: I calculated thisese figures by considering the invoice date, not incurred date.

Please show me an example of how to calculate it.

Sentence 3: I used confirmed figures byfrom Daniele.

He is in charge of the audit of Uffucine Sla.

Sentence 4: Exchange gains/losses are done bywith the ex-change rate which is released by Central Bank.

Sentence 5: I don't understand what is wrong with that.

Because yYou wanted me to use the government's ratios and I used them.

Either combining these two sentences with "because" or leaving them separate but removing the word "because" would work.

So I used them for the calculations.

I will try to find a way to reach the conclusion you wantare looking for.

Sentence 6: You can see my answer in belowthe e-mail below.

Please take a close look at them.

"At them" is plural, but here your sentence directs to "the email" which is singular. But you could just write like this.

I could not adjusted e the Excel file the way you wanted , because I returned my PC to Mr. Daniele.

Writing Mr. Daniele means Daniele is their last name. If Daniele is their first name, leave off Mr. and just write Daniele here.

Sentence 1: You wanted me to adjust the sales by considering official ratios which wasere published by government.

Since "ratios" are plural, we use "were" instead of "was"

Corrected spelling on government, ratios

The ratios in September and in December awere different.¶
¶
(Alternatively: The ratio was different in September and December)

If we're talking about multiple ratios we'd use the first one.

If you're talking about a change in the same ratio over time, you could use the second alternative, but you've been using plural ratios elsewhere, so sticking with ratios throughout.

But even if it's the same ratio measured at two different points in time, you could still use plural ratios for that. Whereas if there were multiple ratios (e.g. your margin and some sort of export limit) then you'd have to use plural ratios

If you apply the same ration in September to the cancelled sales in December, the net effect would be zero.

I think as we get further into this post, you probably want "rate" / "rates" instead of "ratios".

But (in this time, - then?) , the P&L statement included in the Corporate Tax Return will be more different than the one I submitted you.

I'm not fully sure what you meant by "in this time". Maybe you mean "then", which you could use if you're talking about the effect of taking the action suggested by the other speaker.

Sentence 2: I calculated thisese figures by considering invoice date, not incurred date.

"these" figures should be used because you're talking about more than one figure.

Please show me an example of how to calculate it.

Thisat way, I can revise it.

Sentence 3: I used figures [that were] confirmed figures by Daniele.

You usually would omit the "that were" but it is implied in the sentence.

He is in charge of (the audit of / auditing) Uffucine Sla.

Sentence 4: Exchange gains/loses are done bycalculated by the ex-change rate which is released by the Central Bank.

Because yYou wanted me to use government's ratios and I used them.

Sounds more natural to omit because here.

So I used them for the calculations.

I will try to find a way to reach the conclusion you want.

Sentence 6: You can see my answer in the below e-mail.

I could not adjust thed excel file the way you wanted , because I returned my PC to Mr Daniele.

Is Daniele a first name or last name? You used it on its own earlier in the piece, which made me think it's a first name. If it is a first name, we wouldn't use "Mr" with it.