At 30 days, you are past the normal period for a straight out new exchange. At this point, its under warranty (if whatever happened is covered).
Rogers can send the phone out for you to be repaired.. but would be a while without one, etc.
I beleive, they offer a sort of exchange sometimes on those phones, where there is a $35 fee, and you get a referb working unit back (still full waranty coverage though)... Meowmix is more of the expert on that part.
Since you passed the 15 day return policy, you can go to the store and send it into repair. That will take 2-3 weeks or even more to get it back tho.
There is another option. You can contact Rogers tech support and ask them to send you out a refurb S4 if available for $35. This fee is added on your next invoice and is charged for them sending it out and u sending yours back. Once they get yours and is deemed physical damage, they will contact and you let u know what the charge is.
Also there is another option called Rogers Handset Protection program and if you physical damage the phone or anything else happens, you pay $125 for a new or refurb model. This is a $7.99 monthly charge on your invoice tho.