I am giving the seller the ability to allow a payment plan for their services. I have an initial payment which the buyer will pay on the date of selection. I have a payment plan amount and a frequencies of weekly, bi-weekly or monthly. I have created stripe plans that correspond to each payment. I have set the workflow to subscribe the buyer to one of those plans based on the frequency input. My problem is canceling this plan once the appropriate number of payments have been made. Any suggestions?