Thanks for reaching out to Canon USA, we're happy to help!
Without knowing a whole bunch about your situation, it sounds like you might have a loose battery/card door. That will cause your camera to power off and not be able to read cards.
We suggest reaching out to our US-based technical support team for some one-on-one troubleshooting so we can get to the bottom of your issue.
If your camera is within its one year warranty period, you won't have to pay to repair it unless physical damage is causing the problem.
Our team can be reached by calling 1-800-OK-CANON (800-652-2666) from 10am to 10pm (ET) Monday through Friday (excluding holidays).
If you're outside of the USA, you'll want to head HERE and select your country/region for support options.
We recommend sending the camera in for repair instead of trying a DIY repair. If you are in the United States, you can get the repair process started HERE. If you are outside the United States, we recommend reaching out to Canon in your country for repair options. You can find Canon in your country HERE.
We hope this helps!