Orphaned payments due to no account on system

I was invoiced for R5500, ur agent said that they are not able 2locate my account. This went on for days. I then went in2 the store on the 30 December 2015. They were also not able to locate my account but I had provided them with my acc number and managed to make a payment of R4000 at Vodacom in Canal Walk . On the 31st December 2015, still not able to locate my acc(provided acc no. and I made a payment of R1500 at Vodacom in Golden Acre. I paid the R5500 which was invoiced and still am nt sure what for because nobody can explain this due to my acc being \Missing\" The R1500 was updated immediately but the R4000 was never updated. I continuously called and email my proof of payments (sent thrice or 4 times) but there was still no success with finding this payment nor my acc so they claim.. by the 28th January I was due to pay an installment &still the R4000 was not found & NOBODY EVER CALLED TO ADVISE ME ANYTHING. I needed to ALWAYS CALL YOU!! Point is, I paid ANOTHER R4000 on the 28 January 2016 (Have my slip) &STILL I HEAR NOTHING FROM VODACOM. Nw I need 2pay R1900 acc 2 ur agent???? I refuse to continue with this contract, I want it cancelled immediately&Not paying anything!"