I have diligently worked on my credit for the past year. My Transunion score had reached 669. In late April, I received a notice from Cascade Capital and I immediately sent a debt validation request. Cascade never responded to my DV letter. The tradeline was never on my report. Today I received notice that my score has dropped to 615 and Debt Recovery Solutions is the Debt Collector with Cascade as the original creditor. I have never received any notice from this collector before. Can I dispute this information with Transunion and provide proof of the DV letter sent? I’m not sure how to handle this. Any advice would be greatly appreciated.