Pay the fee. I have been on an HOA treasurer and these fees are the only way to get people to pay on time. I am guessing you had a month or two to pay before late fees are assessed, that's how we did it. $50 sucks for only 4 days. I would approach the board and apologize for being late, but it was only 4 days, would they settle for $25. If not, pay the $50 and pay on time next year.
[rant on]
Yeah...
That's the ticket...
Knuckle right under to a bunch of anal tin pot dictators more worried about the color of a window shade than the kid running loose in the neighborhood vandalizing mailboxes and planters on porches.
HOA's - arrrrrghhghgh! Unions for snobby, arrogant yuppies. Ya gotta love 'em.
[rant off]