Customer (SPA/Massage Parlor) has enquired if they create a Membership card that offers one massage every month as part of the membership and additional service can be obtained oat a discount, they do want to restrict that no one abuses the system and uses only one visit per month however, if the client cannot make it that unused massage can roll over till the number of massages is done. Currently the only way to do that is remove the number of visits in the membership which cannot be monitored and a client can visit multiple times a month abusing the system. It would be great if the membership offer a way to roll over the unused massages to the following months so the client feels they got the value of being a member.