Please let me know, at your convenience, how the 'reset without batteries and storage' works for the problem - if it does anything at all.
I'm glad to hear that the camera has been well treated... but that, and its status as less than a year old, means that this is likely to be a failure-within-warranty. A warranty covered defect can be remedied by the manufacturer (Canon UK, given that your 650D is presuming a Canon EOS digital camera) at low cost or no charge to you, if you put in a failure-within-warranty claim to Canon UK within 1 year from the purchase date as shown on your sales receipt or credit card records of the purchase - proof of purchase date can be required before warranty claims will be honored, in some cases.)
For the return-to-Canon procedure for warranty service or replacement (whichever one the specific terms allow), see this page:http://www.canon.co.uk/Support/Consumer_Products/Repair_Process.aspx
If your camera is not a Canon 650D, or if you have other queries about the matter, then please Reply and I will provide further assistance as needed.
If the removal of the batteries and storage overnight does not fix the problem at all, and there is no obvious dirtying of the area near the mode dial, then you should go through the return-to-Canon-UK for warranty servicing procedure on the page cited above.
- If this is the Answer that helps with the issue, then rating my Answer positively would be appreciated.