Vend -> Hikashop API integration

Hi guys,
I'm working with a developer to integrate the online point of sale software Vend HQ:
www.vendhq.com/b?utm_expid=30853408-9

With Hikashop. We have the synchronization from Hikashop to Vend working well using the Hikashop API however the other way around isn't so good. How the process is working currently is a cron job runs, calls the Vend API and then updates tables on our Joomla site which map Vend product IDs and Hikashop products, same goes for categories etc.

The big problem seems to be characteristics and variants from Vend to Hikashop (from Hikashop to Vend works well). Because Vend stores these individually for each product how we are currently doing it is during the synchronization, we check all the Vend product characteristics for all products and their characteristics. We then check to see if these characteristics exist in Hikashop and create them if they don't - this works fine. We then check all the variants for the characteristics in Vend and check these against the valeus for characteristics in hikashop, this also works well. Where we come unstuck is that when we add the characteristic to the product in Hikashop, it creates all values as possible variants. Like lets say Hikashop has Size: small, medium large. And in Vend the product is only size: small and medium - large is also automatically added in Hikashop.

Any advice on how to avoid this? This is using a direct database connection. My idea I mentioned to the developer was to get all the variants in Hikashop once the product characteristics have been added, cross reference with those from Vend then delete the excess hikashop ones however apparently this won't work either. This is using the tables
hikashop_product
hikashop_variant

Any advice?

I am looking for a Vend/Hikashop integration solution if there is one available?

Try Vend Point of Sale integration by Octopus. As well, you can create custom integration by using "Octopus API"