ROAMING NOT WORKING

Good Day: I’ve been on a pre-paid plan with MTN since 2004. In October 2017 I travelled to Argentina. Before travelling I visited an MTN store to find our if I needed to register for international roaming and they rep**** no, since roaming is automatically activated on prepaid plans. To my surprise, once I arrived to Argentina, the MTN network disappeared completely! So, I was not able to communicate with my customers in South Africa and had to buy a Skype number and local sim card in order to keep in contact. I didn’t bother much about my MTN number because my return flight was booked for December so I was going to return within 3 months before my number expires. For personal reasons I had to extend my stay in Argentina but as there was no MTN network I didn’t have the chance to make a call or send SMS in order to keep my number active. I only arrived to South Africa on 2 March 2018. Now MTN is telling me that" number ********** 949 has already been disconnected, recycled and resold due to no usage on the number for 90 days or more and is no longer available for reconnection. I run a business and creates lots of complications for me to change my number now, as I have an extensive database of providers and customers plus I’m trying to call my number and is always on voicemail so I’m not sure if indeed the number has been resold." So basically I want my number back! I was told that there was roaming in Argentina on Prepaid but clearly there is none.