MTN Stole my Airtime

<p>on the 6th May I left the country for 3 weeks, before leaving I have over R500 of airtime on my prepaid sim, before departing for Taipie I removed my MTN sim and inserted a Taiwan Mobile SIM, on return on the 26th of May and after langing in Durban I re-inserted my MTN sim into my phone, I immediatly tried to make a call and was met with you are out of fund message. How is it possiable that I use R500+ of airtime while my sim card is not even inserted into a phone ? Shocking !!!!!</p> <p> </p>