Nike Pegasus right back heel part braking lose from my takkies.

I bought myself a pair of Nike Pegasus about 2 years ago I don't expect them to been braking so quickly as I safed a lot of money to pay for the takkies I really like it a lot but it right back side of the sole are breaking loos from the top part of my takkies. I would really appreciate it if you can at least come back to me as I am not an rich guy but I safe to buy me the takkies I always wanted.