Not upholding warranty

Well, I guess spoke too soon in my last post on this company. The exact same issue I had prior to the repairs done by them in September 2019 has since returned. I took the vehicle in in December 2010 as it's still within the warranty period not to mention I had started querying the workmanship 3 days after I initially fetched the vehicle after the repairs in September but kept getting bluffed that everything was fine. They refuse to act on this and deny liability. It seems all those time I was coming to them for a check up on the work they had done they knew exactly what they had done wrong and kept telling me everything is fine in order to push the warranty period. Now they fail to give a technical report on what exactly went wrong and furthermore they wish to charge me storage whilst I lodge a complaint with RMI.