I purchased the Protect Basic a couple of months ago and now want to upgrade to the Protect Plus but have to pay another £80.00 with no discount?

HiI bought a Ring doorbell a few months ago and paid for the Protect basic at £34.99 for the year, I have since added 2 x cameras and want to upgrade to the Protect plus but it is another £80.00, does anyone know if you get a discount for what you have already paid? As I have only had the basic for a couple of months? Thanks.