Migration from Contract to Pre-paid

I'm very disappointed with the service from MTN. I called on Monday 9 May 2016 and spoke to an MTN Consultant named Cleville where I requested a migration from contract to pre-paid due to my unemployment. Email was sent to the MTN Retention Department for an urgent migration - ref no. ***8. Refiloe Mue from the Retrention Department rep**** via email saying migration will occur within 2days/48 hours - ref no. ***. Today (Sa****ay 14 May 2016) I've received my contract minutes, sms' and data where I've told that 13 May 2016 will be my last statement. I will not be paying the next statement (june 2016) account as this is an mistake from your side and I will certainly be migrating to Vodacom, Cell C or Telkom.