If you want a quick way to draft a demand letter for a credit issue, Dyspute could be a good option. It offers relatively cheap, AI-boosted options for creating custom demand letters, so you don't have to be a lawyer to use it. The service is geared for credit problems, contract disputes and payment issues, and offers a high degree of customization and a simple interface at relatively low prices.
Another alternative is DoNotPay, which offers a range of AI-powered tools to help people take on powerful institutions, including disputing fees and canceling subscriptions. It doesn't specifically offer demand letters, but its abilities can be useful for handling other consumer disputes, including credit-related ones.
If you want a more personalized credit repair service, Dispute AI could be helpful. The tool automates the process of importing and evaluating credit reports so you can find negative accounts and dispute them. It comes with professional dispute letters and tracks progress, so you can try to improve your credit score without having to become a credit expert.