Ebucks earnings rate decline no consultation

Since I was 16 years old (I am now 47) I have had a credit card account with FNB. I have had ebucks since they were implemented as an incentive scheme. We now need to pay for the privilege of earning ebucks. Ebucks I have earned monthly, have steadily declined, despite a regular spend through the card. I can monitor this, as I transfer my salary to be spent, through my FNB credit card. I do not want any other account with this bank, as their terms have not been favourable. Apparently this is what I need to do to regain my previous ebucks earnings rate. At this rate I shall migrate my only service with FNB, as there is no incentive to remain a customer.