Slow/non-existent WIFI at certain times of the day

We have been experiencing extremely slow and at most time non-existent wifi for the past few weeks now. We have rest the modem, hoping that this would help. Seems like we just lose connection at peak times, being in the evenings from 7pm-10pm. Also, over weekends, connection is just lost. This is unacceptable, as we pay our bill on time, as requested by Telkom. A fault was logged on 14 April 2016 - 99CWK14/04/06, still we have not heard ANY feedback, or any kind of correspondence as to how this issue will be fixed. It has been 6 days now since we have logged the fault. Please can someone get back to us and assist? This is totally unacceptable as we are YOUR customers, we need to be assisted when YOU are not delivering the service that WE are paying for. Tried calling your customer service centre so many times, but I cannot spend over 30 minutes waiting on you to answer the call. Please assist urgently.