Fidelity National Financial, Inc Debt Collection Complaint

Fidelity National Financial, Inc Debt collection department,

Disclosure verification of debt Right to dispute notice not received California

On - -, -, I sent a certified letter to - -. -, vice president/trial counsel of Fidelity National Law Group, assignee to - Receivables requesting them to verify a debt that has started in -, but until now I have not received anything from them. They placed lien on my property in - and - but failed because the SSN who owes the debt was not mine. They also tried to foreclose on my property thereafter, and that also failed. This debt was not even ever in my credit report. What should I do next? Will you please help me?