Cancellation searches - 'cancel [competitor]', '[brand] overcharging' - look like negative queries. They are not. They are high-intent signals from people who have already decided to leave. Auction pressure is low, CPCs are cheap, and the user just needs somewhere to go.
Most PPC accounts are not structured to capture them at all.
https://www.digiconomy.online/insights/cancel-searches-ppc-competitor-leads/