Telkom - Poor Service (Fiber Speed Half of Promised)

Since early June I've been logging faults using the call center and Telkom App relating to poor fiber speed. I'm paying for a 4mbps line and have not been able to get a speedtest result above 2 mbps since early June. Despite changing DNS settings etc. (as advised by a call center operative) nothing has changed, other than Telkom still charging me for a product they are unable to deliver. According to the call center operative I have just wasted 15 min dealing with, they have yet to assign a technician to the fault - A MONTH LATER! Telkom, you are in breach of contract and unless my issue is resolved by COB 25 July 2018 I shall be cancelling my contract and taking my business elsewhere.