Why are macros from my new DSLR no better than those from my P&S?

I have been using a 14mp point and shoot for a couple of years. I like to take macros of flowers, frost and bugs. I want to keep zooming in on my PC to see deeper into the flower, so I bought a 18mp Canon EOS Rebel t4i with two kit lenses.

I am very disappointed, because the macro pictures from the $150 camera and the$1100 camera look the same.

A 5:1 magnification macro lens from cannon is $1000. Should i get the Nikon 24mp for$650 or save up for the Canon lens? Would tubes help? should i return the canon?