It's quite impossible that the VC downright stole the customer data. There seems to be a mixup where our customer data got into their system. Not sure how to ask them to purge our data without seeming like an asshole.
I guess you could make another "startup" with fake clients and be legally prepared to screw him. Luckily, He will ask for the same info. If the fake contacts are contacted by your competitors, you can use it as proof.