Holder of my Note wants higher %, 3rd Party..

(I live in CALIF, if this helps with an answer on this…)

My wife and I purchased a rental property last year from a distressed Seller who was willing to sell us the property on a Zero-interest junior-lien Note for $23,000 of the purchase price. Now, a year later, they are desperate for money and said if we don’t pay in full “Now” they are going to sell our Note to someone who will charge us somewhere between 4% - 6%.

Can they even do that??

The escrow company made the Note part of the escrow instructions and it very clearly says our terms are Zero interest for 5 years.

If they sell the note, don’t they have to take the loss by selling the Note at a discount for the benefit of a quick, lump payment? It doesn’t make sense that we’d be at the mercy of whatever percentage rate someone wants that we never made any contract with. Any help on this would really help as the Note holder wants an answer from us about whether we can pay them off by Tuesday. Thanks,