Block changing billing cycle upon upgrade
when a product is on one billing cycle, the client can make an upgrade to a different product, while changing the billing cycle. this will cause his to pay more (!) because he actually pays for the upgrade to his entire billing cycke and then for the added amount to the cycle he chose.
there should be a way to prevent clients from changing billing cycles upon upgrade (maybe add a config).if a client want to change cycle, an admin could do it for him.MtK