I have 1-7 set up like this:
DailyReward1:

  Command: eco give [Player] 100
  Slot: 1
  ActiveItem: ENDER_CHEST
  ActiveItemAmount: 1
  ActiveItemGlow: true
  InactiveItem: GLASS_PANE
  InactiveItemAmount: 1
  InactiveItemGlow: false
  Heading: '&6 Day #1'
  ActiveLore: '&7100 Gold & Daily Key;'
  InactiveLore: '&8You have already claimed this reward.;Check back next week!'
  DaysUntilPlayerCanClaim: 0
  TimeToClaimFormat: '&8You can claim this reward in &7%days &8days.'
  CanBeClaimedFormat: '&aYou get this reward today!'
  CanBeClaimedTomorrowFormat: '&8You can get this reward tomorrow!'

and I delete the eighth. But it keeps coming back like this:

DailyReward8:
  Command: eco give [Player] 2000
  Slot: 13
  ActiveItem: CHEST_MINECART
  ActiveItemAmount: 1
  ActiveItemGlow: true
  InactiveItem: MINECART
  InactiveItemAmount: 1
  InactiveItemGlow: false
  Heading: '&6Reward Day #8'
  ActiveLore: '&7Join this server every day;&7You get every day a bigger reward!'
  InactiveLore: '&8You joined some days in a row;&8so get now a bigger reward!;;&7Checkout
    the following rewards.'
  DaysUntilPlayerCanClaim: 8
  TimeToClaimFormat: '&8You can claim this reward in &7%days &8days.'
  CanBeClaimedFormat: '&aYou get this reward today!'
  CanBeClaimedTomorrowFormat: '&8You get this reward tomorrow!'