For breaching rule 13.2, which outlined how players must be registered, the Otamatea premier reserves lost five points from their win against Hikurangi. Those points were awarded to the opposition.
At the time of the infringement, the Otamatea premiers were on zero points and were reduced to -5 points. The club received a written warning for the underage players.
In rule 20.4, it outlined competition points - capped at five - could be deducted from a team, as the result of any player, team management member or club, breaching the competition rules.
The rule does not specify how many points different infringements warrant. In the south zone championship, for example, players who receive red cards cost their team two points.
The club appealed the decision on April 4 but the NRU's original decision to penalise each team five points was upheld.
"We are not trying to play the victim here by appealing, we just don't think the penalty fitted the crime," Otamatea club president Michael Tovine said.
Players are registered via an online process where club officials must press a final button to make them active, as outlined in the rules.
Tovine said a member of the club had simply not pressed this button to finish the registration process which meant the two players were technically unregistered.
"[The club member] was in tears when it happened," Tovine said.
"Obviously, they were pretty disappointed that they had caused it to happen but we are all humans, we do make mistakes.
"We admit that we breached the rule so we do have to wear it a bit, but that doesn't mean we agree with the level of the penalty."
In relation to the underage players, Tovine accepted the club had made a mistake and would be checking player driver licenses and ensuring they had parent/guardian acknowledgement forms from now on.
Tovine said the club's officials would discuss taking this to New Zealand Rugby because he still felt the penalty was too harsh, particularly on a team with no competition points.
However, Tovine acknowledged the club needed to review its processes to ensure this didn't happen again.
"We can't just be the victim, we do realise that there are changes we need to make to be better.
"It's hard to complain when you've been at the bottom for so long because people think it's just a bit of sour grapes which it isn't."
Tovine said instances like reducing the premier side to -5 points on the table would only further impact the relationship between the club and NRU.
"A lot of people around the area down here think that Northland Rugby wants Otamatea out of the competition. Whether that's true or not I couldn't tell you."
NRU community rugby manager Clark Lewis wasn't aware of any issue between the NRU and Otamatea and confirmed the NRU did not want the club out of the competition.
"Although I believe it could have been a potentially unintentional breach of the rules on the club's part, unfortunately for them it is a clear breach of the rules, it's black and white," Lewis said.
Lewis said all clubs had a chance to comment on the rules in place for the 2019 season and felt this instance could be brought up at a review of the rules which was held at the end of the season.