Does give bid to house construction charge fee?

[Yvonne Li]

I was getting bids for my house-addition plan. This company shows up and give me bids after persuading me several time over phone that it is free.
Now after they give me bid, and they send me an invoice for $1200 since I did not pick them as my contractor.
They threatened to put a lien on my property if I don't pay. I am going to call the court and county office and file California dispute one by one. I found this board after searching help on how can someone put a line on your house. I know I still need more detail info for that in CA specifically. I registered in this board since I see lots of contractors here.
Can you please help me? I had thought giving free bids to win 400k construction business is industry standard, isn't it? There are tons of general contractors out there, I never even think anyone would charge for doing that. On this board, does any contractor charge homeowner for preparing bid? If you do, do you tell the homeowner before giving the bid? How do you tell? Do you just say I will charge you this $$ for giving you bid or you simply say I will charge you for doing that or you just don't tell and charge later? How is it legal for contractor do that?

Back to the lien question, does any of you ever put a lien on a house? What is the process in CA? Do you need to show proof-does the proof need to have homeowner's signature or simply an email asking for bid is a proof?

Please help. Thanks.