External Collector dispute

Wonga handed over my account to Shapiro shaik attorneys I paid off the amount that was outstanding. I paid ssda as the nominated external Collector R6200 on the 22nd of December 2021 I requested a paid-up letter from SSDA they are refusing to give it to me telling me about a turnaround time of 21 days. I contacted Wonga I once I established that the money I paid was received and allocated they promised to take it up with as SSDA this was on the 27 of December they gave me a turnaround time of 72 hours to resolve the matter and I should follow up there after. I followed up on the 4th of January 2022 to find out there was no feedback on my escalation therefore I requested they re-escalate my query or complain and to provide feedback today. I phoned all day and no one picked up the phone therefore I'm demanding that someone investigate my complain. I have made payment I've sent the proof of payment to Wonga and requested that they investigate with the external collectors and rectify as they are that the ones that nominated this company to collect on their behalf therefore they should ensure that monies are received and the records are updated accordingly. I demand that someone investigates and provide feedback within 24 hours. I will not hesitate to escalate this matter to the ombudsman and NCR. It is unfair that you can list someone once a person comes and rectify that the accounts the company nominated are unable to do what they are hired for.I have never had a problem with wonga as a company and I know them to be very professional however the company that you have nominated as your external Collector I sputting putting a bad name to your company as they do not offer your clients a proper service I would like my matter to be resolved soonest and for someone to contact me to get details to ensure that this this issue is resolved urgently.