To resolve the issue of incorrect quantity, amount, and price in your generated E-Invoice, you should cancel the E-Invoice either from the portal or within BUSY. In BUSY, cancel the voucher, and when prompted, confirm that you also want to cancel the E-Invoice by pressing 'Y' and then proceed with the cancellation. After canceling, you can generate a new E-Invoice with the corrected details, but it must have a different invoice number. According to the E-Invoice portal, you cannot generate a E-Invoice using the same invoice number.