laravel cashier stripe - How charge customer immediately when changing subscription with the same interval

Question

I implemented laravel 5.2 with cashier (stripe).
I have three plan:

1. Basic - monthly
2. Pro - monthly
3. Agency - monthly

Now if I have customer that subscribe to Basic plan and he decided to subscribe to Pro plan. How can I charge him immediately with cashier?

From Stripe I got the answer that

if customer was in Basic plan and subscribe to Pro plan than hi will charge in the next charge day. but if he subscribe to a plan with a different interval (annually instead monthly) he will charge immediately.

How I can handle this bizarre situation?

Let's say the customer subscribe to a basic plan (the chipper one) paid it's first month, and day after change to Agency plan (much more expensive) and then he cancelled is credit-card. He will enjoy almost a month if Agency plan while he only pays for the Basic plan, and at the next charge day... he won't be charged because his credit-card was cancelled.