Help scammed by s4 sprint , told it was i9500

[AC Question]

i purcahsed s4 . which shows i9500 model inside the software information. but when i entered the download mode it showed sprint sph-l720. and it was making problems of hanging so i took it to market and install stock rom for sprint. Now it is not running my sim. so is there a way to intall back the custom rom of i9500 on my sprint's s4 sph-L720 . ?? if yes so plz any one guide me. and give me the link to roll back on custom i9500 rom thanks