Paid up letter

Mbd just a bunch of *********** people after my first complaint here at hello peter I was happy to receive a call from mbd and I thought that I will get help but it has gone to worse the person who was handling my complaint is no longer answering my calls and emails when I call the call center they tell me my case is still under investigation. My question is how long must I wait for your invistigation I paid my account on the 10th of February with the help of your consulted and it cleared on the 16thof February I gvxae you Pop its in black and white and the invistigation that you are waiting for its ruining my credit profile. Second complaint I paid my Vodacom account in full on the 06th of April and I called call center for paid up letter till to-date I'm still waiting every time I call they will ask for my email address to send the paid up letter but nothing. I'm very disappointed with the level of service I've received 😞😞😞