Suppose an organization have advertised to provide multiple services throughout the course of a year. Each service is sequential, one begins as the previous ends.
The organization has advertised that at the end of each service, you are allowed to choose the next service from a pool of services. Service X, Y and Z caught your attention and you decide to apply. Note that service X and Z is only available in the second half of the year.
Half way through the year, as your 5th service is coming to an end, this organization informs you that both service X and Z have been removed from the pool, and is no longer available.
Suppose your contract did not explicitly state that the organization reserves all rights to modify the service pool, would this be illegal?
If so, what are your legal options?