Expensive Insurer - same as Cheaper insurer

Have full comprehensive insurance vehicle and household. Swing gate broke so I decided to submit a claim to replace the motor. All contractors advised it be changed to a sliding dur to the weight of the gate as replacing the motor will only lead to it breaking again. First assessors feedback onsite was Yes it must be converted..reported back that it was a defective installation and pier wall will fall. Second assessor similar, to have it converted. Insurer rejected both claims saying its a defective installation. House has been insured as is when bought. No alterations done to existing. Reported to Ombudsman. Any other advice?