Billed for Back Dues by HOA, No Contract

[BigCrisco39]

My question involves a condominium located in the State of: CA
Me and my wife bought a condo in Lincoln CA. We have 2 HOA's. After buying the proporty we recived paper work from everybody. HOA, PG&E, City and State. Signed all paper work/contracts.
8 months later we wanted to get in to our pool on site. I talked to our HOA and the told me to contact our 2nd HOA. I called them and they said they would send out a key for the pool. Only problem is we never recieved a key but instead a bill. They want 8 months of back fees, late payment fee and they stamped it stating we have 1 week to pay or it goes to colections.
The bills has 8 months of dues all dated 7/18/11. The date i called about the pool key.

I haver never signed a contract with them, they are not listed in escrow and we have no paper work with there name on it at all. This letter is the only thing we have ever recieved from them.
What are our rights on this bill? Should i just pay this months HOA? Can i tell them to shove it? Do i need to suck it up and pay?
This is our first house so i have no ideas what our rights are.
Thank you for any help,
Chris
PS we have never sent them a payment because we have never recieved a bill.

[Mr. Knowitall]

I expect that you committed to join the HOA and pay dues in association with your purchase contract and through your deed, neither of which I'm in a position to review. What does your deed say?