Is there any way we could get undo/redo functionality in KMM?

Where should this message be sent? (this is a forum, so probably not the best place for a feature request)

As far as I know, there is no undo/redo functionnality

You can report bug/feature request here
https://bugs.kde.org/describecomponents ... t=kmymoney

Undo/redo functionality is already available in the development (experimental) branch of KMyMoney.

Stay tuned, as we hope to release it sometime in Q1/Q2. In the meanwhile, you can test it using the Nightly builds (http://binary-factory.kde.org), however please make sure to use a testing copy of your .kmm file with it.