How to authorize card after payment been captured or authorized for the difference in amount only
We are using Magento version 188.8.131.52
We sell extremely high value goods, the average ticket size is $1500
Our time to ship out the orders is about 3 weeks.
We use an extension that allows us to edit the order and add/remove products in the same order without canceling the original order.
A lot of times, customers will place an order and after a few days, they will call and ask to add something more to their order (so that they do not have to pay shipping charges twice) or ask to change the original item ordered.
Because of the high value of our goods, we cannot re-authorize the complete transaction because re-authorization is valid only for 115% of the original amount upto a max of $75. This will not help us because if customers add another item, it will cost a lot more than $75.
If we were to cancel or void the original authorization, we risk losing the complete sale if the new authorization does not go through. Given the high values of the transactions, there is a good possibility that the new authorization may not go through right away.
A typical example is - A customer places an order for $5000, we authorize and/or capture it, after 1 week, the customer calls in and asks to add another item worth $400. If we cancel the original authorization, we may not be able to get authorization for the new charge of $5400 because If the customers card has a limit of $7000 for example, it will get declined.
So, is there a way for us to only get authorization or capture just the balance amount of $400