Poor service and communication

I have a Samsung S4 phone which I registered for the repair warranty as soon as I received it on contract from MTN. As I understood the warranty, I would receive two free repairs/replacements (one water damage/one screen damage or two water damage etc) <br> My phone was sent to the Canal Walk Samsung repair centre early last year for water damage. My phone was repaired/replaced without any hassles. At the end of last year my phone fell and the screen cracked. Again I sent it to the repair centre. I then received a phone call stating that my phone was no longer under warranty as during the water damage repair, Samsung had replaced two parts so I had already received my two free repairs. This was at no time communicated to me after the first repair by either MTN or Samsung. Neither was the way the warranty worked properly explained to me by MTN. I find this whole warranty issue very misleading and I received poor service from Samsung and MTN. <br>