Softonic's legal information page says (formatting by me):
"For the purposes of preserving any possible intellectual property rights in the event a user or third party believes that their legitimate rights have been infringed due to the inclusion of certain content on the website, email@example.com must be notified in writing by sending an email to firstname.lastname@example.org. The following information must be provided:
- The personal details identifying the owner of the rights that have allegedly been infringed. If the complaint is submitted by a third party who is not the owner, the capacity in which he/she is representing the owner must be indicated.
- A description of the content that is protected by intellectual property rights and its location on the website.
- Evidence of the existence, ownership and validity of the intellectual property rights in question.
- A clear declaration that the complaining party will take full responsibility for the accuracy of the details and information submitted in the notification discussed in this section."
If you haven't done that yet, I'd suggesting sending such a notice, taking care to comply with each of the requirements to the letter.
If you have done that already, and they refused, the next step should be to talk with a lawyer.