Reckless sub-standard repairs refusal to fix

Having had repair-work done on my vehicle through a claim done my vehicle developed a problem rendering it undrivable. My mechanic assessed the vehicle and discovered various problems with the work done by the appointed workshop which led to my vehicle's damage, including non-standard & sub-standard parts being used (cable ties being used to secure panels VS the required standard couplings). Having reported the problem to Dial Direct, the assessor appointed confirmed these conditions present on the vehicle and requested that the appointed workshop correct the work was done as well as cover the costs involved. Over 35 days after reporting this situation, the workshop responded by repudiating the assessor and my mechanics (a specialist on this make) findings. The reasons communicated are not in any way correct, clear or properly substantiated. It is very clear however that sub-standard work has been done. Owing to the excessive period without any action taken or reasonable response, my vehicle is in danger of being sold to recover costs as well as being subject to additional storage costs.