You will either be stuck with them forever or go through a nightmare to move to another system. You WILL lose your verified reviews, which we all know are vital to selling online.
Not only are they terrible for SEO, they hold you hostage, which should be illegal. A customer's data belongs to the customer and should be available to take with them wherever they choose to go, especially when the customer is paying for the service.
I hope they go out of business or someone files a class-action lawsuit against them.