TU states that since they already investigated 3 times - my case is frivolous and all future investigations will not happen. This is BS - the collection co refuses to validate, refuses to acknowlegde my letters even after signing them. ACA had ruled against them - and I'm still getting nowhere. Plus, TU will not post a dispute on file concerning this matter nor tell me what method they used to investigate. Should I just sue both TU and the collection co for being @$$-holes - any suggestions would be helpful.