Are the evap canister hoses defective or not properly installed?

What is your question?

Computer codes P0445 and P0441 keep coming up every 35 miles on my Vibe(17K miles). The original evap hoses had metal clamps and a flex rubber type hose on it. The replacement hoses and Evap Canister has only hard plastic with plastic clamps on some of the hoses, but none on some of the fittings. I'm going back for the 4th time to Trotter Long Pontiac in Chattanooga. The last time they said a hose came off. It looks like the hoses are not secure and they changed them from the original hoses. Has this been a problem with the newly engineered design of the replacement Toyota evap canisters, or should I go some place else for service? My last 8 vehicles have been GM, and I'm disappointed with the Vibe. It's more Toyota than GM.