Within ten days after a home solicitation sale has been cancelled or an offer to purchase has been revoked, the seller shall tender to the buyer any payment made by the buyer to him and any note or other evidence of indebtedness taken in the transaction. A provision permitting the seller to keep all or part of any payment, note or other evidence of indebtedness is in violation of this section and unenforceable. If any down payment included goods traded in, the seller shall return the goods in substantially as good a condition as when he received them. If a seller has failed to tender goods as required by this section, the buyer may elect to recover an amount equal to the trade-in allowance on such goods as stated in the agreement. Until a seller has complied with all the obligations imposed by this section, a buyer may keep any goods delivered to him by the seller and he is hereby given a lien on such goods for the purpose of making any recovery to which he is entitled by this section.