Query about h form

Hi friends,I have a query.please help me.

There is a company in chennai say 'A' which has a branch office in Andhra pradesh say 'B'.There is also a sister concern in chennai for company 'A'.The sister concern is completely into exports.

The sister concern has an export order in hand.To export the goods,they have to be packed in bags which were bought from a dealer in Andhra Pradesh.Branch office 'B' has packed those goods and sent them to the sister concern for export.The dealer has raised the invoice on the branch office 'B' and asking for a 'H' form from branch office 'B'.

My query is whether the dealer should reissue an invoice in the sister concern's name as the export order belongs to the sister concern and take 'H' form from the sister concern?

or

Is there any other treatment which can affect all the three parties viz. dealer,the branch office 'B' and the sister concern?

this is urgent. and thanks in advance.