There is only so much you can do that is cost-effective, given your camera was released in 2007. It is extremely unlikely that that it can be serviced if you cannot find an easy fix yourself, so you may have to consider getting a newer unit. There are many units to choose from and you may get a discount from going through Canon's trade-in program.
cheers, TREVOR
The mark of good photographer is not what they hold in their hand, it's what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
