What is the upgrade/downgrade policy?

If, while on a monthly subscription, you wish to upgrade to a higher-priced model, that will only be possible subject to our availability and there will be an additional charge corresponding to the difference in price between both models for the remainder of the months left in the subscription. If, while on a monthly subscription, you wish to downgrade to a lower-priced model, that will only be possible subject to our availability and there will be no refund or compensation in place. If, while on an annual subscription, you wish to upgrade to a higher-priced model, that will only be possible subject to our availability and there will be an additional charge corresponding to the difference in price between the price of the outstanding months on the original annual subscription and the price of a monthly subscription of the new model for the number of months remaining. If, while on an annual subscription, you wish to downgrade to a lower-priced model, that will only be possible subject to our availability and there will be an additional charge corresponding to the difference in price between the price of the outstanding months on the original annual subscription and the price of a monthly subscription of the new model for the number of months remaining. In case that difference results in a negative value, there will be no refund or compensation in place.