making false claims - activity band

Am very upset with Discovery. Wanted to get an activity band and saw on the Discovery website 3 weeks ago that we could claim for the full amount from the available funds in our Medical Savings Account (MSA). After placing an order with Dischem, I was finally able to get the device yesterday. However, I discovered then that Discovery had suddenly changed their policy and now we can only claim back R750 for the device, and fund for the rest from our own pockets! I think it is terribly ********* to make such a claim to attract customers and then reversing it whenever they like. This is alarming and very unfair to the customers. Customers will expect certain benefits but will be told otherwise as Discovery pleases. Does this also mean Discovery can remove any part of their policy as they please without giving notice? I hope Discovery takes this seriously and rectify this.