AirHelp Compensation Refusal - Flight Canceled Due to Technical Issue

After the airline canceled my flight and sent me an email saying, "technical issue, we can't use the aircraft you would be flying with," AirHelp looked into my case. I missed my connecting flight to another country because of this cancellation. I was only able to book a new flight 12 hours later on a much longer route. AirHelp decided that there would be no compensation for this flight even though the airline wrote that there was a technical problem. What worries me the most is that the airline now seems to be giving a different reason for the cancellation, and AirHelp just went along with it without really looking into the clear evidence I gave them.