We have three subscription plans, and all have a monthly and yearly option.
If a user is on the Plan 1 (Monthly) and want's to upgrade to Plan 2 (Monthly) That works just fine.
However, if they want to upgrade from Plan 1 (Monthly) to Plan 1 (Annual) the option is not available.
Please advise how to fix this.
PS. you can also see the subscription plans here http://www.101businessinsights.info/subscription-plans
and the upgrade options here