"Immediately" per the title, mortgage refinance loans and many other consumer loans are covered by the [Truth in Lending][1] Act providing a Federal 3 day "right of rescission", where you can cancel the loan within 3 days and owe nothing.  

Pennsylvania separately provides a 3 day [right to rescind][2] for any contract over $25 where a salesperson called or came to your house.


  [1]: https://www.occ.treas.gov/topics/consumers-and-communities/consumer-protection/truth-in-lending/index-truth-in-lending.html
  [2]: https://www.attorneygeneral.gov/protect-yourself/consumer-advisories/your-right-to-rescind/