Thank you for your question.
Yes you can. South Carolina has a 5 day time period in which a contract
to purchase a timeshare may be cancelled. As you just signed the documents today, what you should do is send WRITTEN confirmation to the seller that you have changed your mind and wish to cancel. Be sure to send it certified mail or with proof of delivery confirmation.
It's not a bad idea to, as a back-up, also send it via regular mail as well, though that is not required.
Here is the applicable law:
South Carolina Code of Laws Section Title
27, Chapter 32, Section 27-32-40:
SECTION 27-32-40. Furnishing copy of contract to purchaser; terms thereof.
(A) It is a violation of this chapter for the seller of a vacation time sharing plan to fail to utilize and furnish the purchaser a fully completed copy of a contract pertaining to the sale at the time of its execution. The contract must include the:
(1) actual date the contract is executed by all parties;
(2) name and address of the seller;
(3) total financial obligation of the purchaser, including the initial purchase price and additional charges to which the purchaser may be subject;
(4) specific term of the contract; and
(5)(a) following statement in immediate proximity to the space reserved in the contract for the signature of the purchaser and in bold type:
"YOU MAY CANCEL THIS CONTRACT WITHOUT PENALTY OR OBLIGATION WITHIN FIVE DAYS AFTER THE DATE YOU SIGN THIS CONTRACT, NOT INCLUDING SUNDAY IF THAT IS THE FIFTH DAY, OR THE DATE YOU RECEIVE THE DISCLOSURE STATEMENT PURSUANT TO Section 27-32-100, WHICHEVER OCCURS LATER. IF YOU DECIDE TO CANCEL, YOU MUST NOTIFY THE SELLER IN WRITING OF YOUR INTENT TO CANCEL BY SENDING NOTICE BY CERTIFIED MAIL, RETURN RECEIPT REQUESTED, OR BY ANOTHER VERIFIABLE MEANS, TO (NAME OF SELLER) AT (SELLER'S ADDRESS)."