Yeah, but reading it, it's not that bad. Compared to before the earning double points promotion - which they have no plans to stop - you're better off.
£100 used to be £1 voucher - 4x for rewards = £4 rewards.
£100 now gives £2 voucher cos of double points - 3x for rewards from Dec 6th = £6 rewards.
Ok, I agree that between the start of double points earning and Dec 6th (When new rules about rewards come in) that £100 gives £8 rewards, but at least you know, so you can make the most of the vouchers before it happens.