What to do next?

Question

I have had my car in the shop two weeks now. I first took it in because it wouldn't switch gears...so they then put a new conductor plate and filter on it...I got it back drove it a couple hours it went back to not wanting to accelerate after I caught speed.So I take it back to the shop .they keep it a few days changing the filter again.they say its ready again i drive it a couple hours it till do in the same thing so I den I turn it off and back on it get a lil miles down the highway in it do the same thing...so I take to another mechanic and put it on a machine it two codes Po715 and po700....I have no idea what to do next????