What year/make/model is your Kia? Is your check engine light on while driving?
Your electrical problems are most likely due to a faulty ignition switch and are not related to the fuel filling problem.
The fuel filling problem is likely due to blockage in the two way valve or the evap canister. Both are near the fuel tank and are shown in the picture below. Inspect the lines going to the valve and to the canister before replacing either part. The fuel tank must vent through these lines and the canister when filling the tank. Also remove the filler neck and check for obstructions in the filler neck.
Attachments are only available to registered users.