Cal. Civ. Code § 1803.7
The seller shall deliver to the buyer at the time of the buyer's signature a legible copy of the contract or of any other document which the seller has required or requested the buyer to sign, and which he has signed, during the contract negotiation. In addition to the penalties provided under Article 12.2 (commencing with Section 1812.6) of this chapter, until the seller delivers such documents, the buyer shall be obligated to pay only the cash price. Any acknowledgment by the buyer of delivery of a copy of such documents shall be printed or written in a size equal to a least 10-point bold type and, if contained in the contract shall also appear directly above the space reserved for the buyer's signature. The buyer's written acknowledgment, conforming to the requirements of this section of delivery of a copy of such documents shall be a rebuttable presumption of such delivery and of compliance with this section and Section 1803.4, in any action or proceeding by or against an assignee of the contract without knowledge to the contrary when he purchases the contract.
If the holder furnishes the buyer a copy of such documents, or a notice containing the items required by Section 1803.3 and stating that the buyer should notify the holder in writing within 30 days if he was not furnished a copy of the contract or of any other document which the seller had required or requested the buyer to sign, and which he did sign, during the contract negotiation, and no such notification is given, it shall be conclusively presumed in favor of the third party that copies of such documents were furnished as required by Sections 1803. 4 and 1803.7.
Ca. Civ. Code § 1803.7