Pause stripe subscription for x months and the remaining amount not us

You can "pause" a subscription in two different ways:

1)if you already know when the pause should end, you can update the subscription with trial_end set to the timestamp of the next desired billing date, and prorate set to false.

2)if you don't know how long the pause will last, you should cancel the subscription, and create a new subscription when you want to resume billing your customer.

If you want to refund for unused time, you'll have to compute the amount of the refund then create a (partial) refund using the subscription's latest charge.