The refund policy of the Co-op is discussed in the membership agreement that all members sign when they join. To quote:
Upon notice in writing to the Co-op, I may resign my member-ownership.
My accumulated investment balance (without interest but including any
accumulated patronage refunds), with the exception of a $10 processing
fee, will be refunded when the Board of Directors determines the Co-op
is in a financial position to do so. This will be no sooner than two
years after the official store opening. I understand that a refund may
take some time and I agree to this waiting period. I also understand
that I can donate this money to the Co-op by writing to the Co-op,
specifying the amount and date of the donation. If I move and do not
provide a current address to the Co-op, I understand that I forfeit the
right to receive a refund.