Plan price change does not reflect existing subscriptions

Plan price change does not reflect existing subscriptions

Hi, 

I have encountered an issue with our Zoho Subscriptions setup where if I change the price of a plan for our product, e.g from $2 to $5, the price increase does not update on the existing subscriptions. This is important as, although price changes are not happening often, we most definitely need a way to amend the price of a plan in a seamless way without inconveniencing the customer to subscribe again. I feel that this is a fundamental functionality of subscriptions/product management. 

Our use case would be: 
  1. The customer starts a subscription (Subscription 1) for plan A costing $5
  2. Change plan A's price to $2 
  3. On the next bill date, charge Subscription 1 the new amount which is $2*
*This must work for all active subscriptions

Could you please advise on the best way to achieve this?

Thanks,
Rositsa