Unallocated payment

I have a Netstar account and it was handed over to Nimble collection and I made a ptp with them which was paid however my second payment I used an incorrect reference but emailed the POP and the payment was made on time I sent the proof numerous times and still the account was not resolved. The team manager received the POP a couple of times and she requested that I send them an email back to explain that an incorrect reference was used which I did but still the account was not fixed and I even sent the proof to Netstar and explained to them my problem. I kept on receiving harrasment calls and with a nimble the add an additional charge if they call you so I kept on explaining the same story over and over to numerous people the team manager Abeeda did not sort the matter and I decided to copy Netstar on my email to nimble and I also contacted Nomsa cibisi the legal controller at Netstar till today I am waiting for feed back from Nimble, today abeeda said that the matter is still being investigated I am wondering what are they investigating as pop was sent it is just to look at their bank statement and allocate the payment but for them it is difficult. I was informed that the turnaround time is 48 hours but the time has lapsed already and matter is still not sorted