It took me couple of minutes, you can get the breaker from Home Depot, around $3 tax in I think. It's a black piece similar to the ones in figure 4 and 6. I was lucky.
An electrician can do some inspection.
their cable may be cut down by mouse(地线,NOT 火线). i met the kind of the problem before. only some of outlets didn't work. i tried to fix that like you. checked the panel and big electric equipements, that cost me one day. the workers from Hydro just use five min. to recover the power, even didn't come in my house.
haaa... i was stuck with the same problem for one week last year. it is about the correct method to turn on those GFCI breakers (normally with TEST button):
If this kind of breakers cut off the power, their handle/switch always stays in middle of the state (neither "ON" nor "OFF"). In order to turn on, you will need to pull the handle to "OFF" at first then push it back to "ON". You can not just finish the job by simply pushing it back to "ON".
Those breakers are very expensive, so don't throw away the old ones before you have tried everything you could