stripe payement /membership bug

Hello
I don’t want the vendors to be able to pay 0 euro again if they cancelled their membership’s plan during the free month because they changed their decision and decided not to continue with my website but if after they changed their mind again and decide to register again then
they will pay the price without free plan in that case EVEN if it’s another type of membership’s plan
So if they were already registered with a free month ONCE but they cancelled it on their own even if the free month wasn’t expired they will need to pay directly
Because I cancelled a plan to test it and I could register with the same plan again or another one and still have the free month so If I can do that vendors too and indefinitely and I would be screwed
here’s the link of my website : https://beantic.wpcomstaging.com/my-account/ so you can try it if you want it’s in test mode
Can you fix that please as soon as possible ? 🙂
In waiting for your response
Good to you,