претензия(A persuasive letter sent by a customer to a business or agency to identify a problem with a product or service. Also known as a letter of complaint. Typically, a claim letter opens (and sometimes closes) with a request for adjustment, such as a refund, replacement, or payment for damages. A reply to a claim letter is called an adjustment letter. Alexander Demidov)
претензия(Letter of claim (previously known as a "letter before action" and also referred to as a "cease and desist" letter) to be used in relation to infringement of unregistered design right, with separate undertakings legal-zone.co.ukAlexander Demidov)