Upsell, cross-sell and retention

Hello,

We sell our services through subscriptions, counted by point of sale. Whether a business has 18 points of sale or 210, they should be able to indicate the quantity and modify it later. Is it possible with Zylvie?

Can the customer modify the services, quantities and options they've subscribed to, cancel complementary services or add new ones?

If they intend to cancel the main service, can we trigger a retention strategy in your system that would activate messages in the customer portal to try to retain them, with a price reduction for x months, or by offering an optional service free of charge, for example?