I too find it very difficult to remove the Smartron SRT Hard Case which I also bought from t store abt a year back. But now this is what I do if I want to remove the case,
First of all I take out the phone from top left side (i.e. case from the audio jack side) just that the phone is out of the case, than from the right side so that the phone is out of the case from the top side and than just take out the phone it will come out easily.
But take precaution that when u take out from top left side u have to hold the phone and than try to remove from top right side otherwise it will go back into the case from the left as soon as u try on the right side.
This method might not work for all, as when we try to take the phone out from top right side power button might get pressed.
So if it happens for u try this,
As u can see that the SRT phone doesn't have any buttons on the left side of the phone,
So now take out the phone from the bottom left side (i.e. case from the speaker side) and than try to remove from the top left side (i.e. case from the audio jack side) now just take the phone out side ways.
I hope u get what I am trying to say.