Telkom LTE speeds in fish hoek cape town PLUMMET

case number Case ********** 5 almost a month old...no technical input i have the uncapped LTE...speeds usually 50 megs plus..had it for 2 years...on month to month now...suddenly my speeds have nose dived to 15 to 20 megs and even at those speeds i cant watch a simple netflix episode as all it does is bufffer buffer buffer...why is even a BAD 20 meg line buffering...before the speed drop we had 4 devices streaming and NO buffering even my bad 4meg adsl at work can watch a movie what is going on..im paying R600 a month and cant watch a simple miniseries at night