Unpaid providen funds

Hello everyone iv worked for a company called mos tyres in durban iv resigned in May our union called mibco paid me a portion off my providen fund and I'm having a hard time getting balance of my payment it's costing me me alot of airtime and data emailing mibco this week only it costed me over R250 airtime and over 500megs of data please can anyone advise me how to resolve this issue as I'm unemployed and I need if my funds and I'd like to be reinburs my airtime and data from mibco