Arrange data based on cell postions

I have a list of exported data (grey area) where the export does not put the account number to the side of each transaction.

In the example I would like the account number in column C to appear against each transaction as shown in column E

There is always different ammount of transactions per account.

The name "account" is always in the left cell of the account number and the customer name is in the right cell next to "Account" and could maybe used as markers !!

The data in the grey area is the raw export data which is just a small sample of an export that has thousands of trans.

Any help appreciated.