Option to Upgrade a Client's Plan without Cancelling Old Product

I put clients on 12, 28, or 52 week programs. Within these programs, clients can train 1, 2, or 3 times per week.

Sometimes, a client will be training for, say, 12 weeks at 1 time per week and decide halfway through that they want to train 3 times per week.

Currently, the only way to do this is to cancel the current product and start a new one, but if the person doesn't want to start a NEW 12-week program, and just wants to complete their CURRENT 12-week program at a higher training frequency, there is no system in place to do that.

It would be nice to just be able to click "Upgrade Current Plan" and have Trainerize adjust the billing to accommodate this. For a Paid in Full program, the client could have a pro-rated amount charged for the additional sessions. For an installment payment plan, the plan would automatically start billing at the new rate next billing cycle.

This will help trainers sell to their clients because there will be fewer steps standing between the client and an upgrade.