Wrong Vendor Invoice Posting Due To Wrong Excise Tax Code

Question

Hi:
We have created a Purchase Order as per below:
Qty     10
Price     100
Value     1000
Excsie 10%     0
Cess     0
SECess     0
Value+Excise     1000
VAT 5%     50
ValueExciseVAT     1050
(Please note that the PO was to be created in the following fashion as the Material was excisable)
Qty     10
Price     100
Value     1000
Excsie 10%     100
Cess     2
SECess     1
Value+Excise     1103
VAT 5%     55.15
ValueExciseVAT     1158.15
We did the Goods Receipt and the FI Document is as follows:
24340000     Paper Stock     BSX     1,000.00
13110100     GR/IR-ext proc     WRX     1,000.00-
We did the Vendor Invoice Posting as follows:
100183     SIEGWERK INDIA PVT LTD (SICPA)     KBS     1,050.00-
13110100     GR/IR-ext proc     WRX     1,000.00
24638100     VAT Recoverable     JP5     50.00
The Material was issued to Cost Centre
Later at the time of Excise Invoice posting, we came to know that the Tax Code in the Purchase Order was wrong. Here in our case, we have created separate Tax Code based on Excise Percentage. For example, V1 for VAT 5%, E1 for VAT %+Excise 10.3%.
To post the excise invoice, we changed the Tax Code in the Purchase Order and did the Excise Posting as follows:
24820020     CENVAT Inp SHEcess     1.00
24820000     CENVAT Inp BED     100.00
24820010     CENVAT InpEcess     2.00
13113920     CENVAT clearing     103.00-
My Question:
a. Is this the correct way?
b. What about the following FI Entries which got generated when we do the MIRO with actual Tax Code:
100183     SIEGWERK INDIA PVT LTD (SICPA)     KBS     1,158.15-
13110100     GR/IR-ext proc     WRX     1,000.00
13113920     CENVAT clearing     JI1     100.00
13113920     CENVAT clearing     VS9     2.00
13113920     CENVAT clearing     JI6     1.00
24638100     VAT Recoverable     JP5     55.15
Please guide.
Regards,

Answer 1

Thanks Sanjoo for the reply.
Here my worry is the all the postings have been made in SAP in Production Client.
The User has already done the postings for MIRO & J1IEX without informing to us, and the volume of transactions is huge.
We are in the back-log mode and at this stage, we can't go for any reversal . I am Just exploring the alternatives.
Our MM & FI Users are little bit smart, when ever they do some mistake, they simply say "we will pass a JV" and we are not able to educate them that the JV is not a Solution. Please guide.
Regards,
PK