Slow Lte and High latency/ping

<p>For the last month there is a problem with botg my lte data routers from telkom. During the day I get speeds of up to 29mbps download and ping of 40ms but from 17H00 in the afternoon my ping shoots up to 400ms and download speeds goes down up to 0.5 mbps. A person from telkom came 2 weeks ago during the day and tested but evereything were fine at that time. I explained that after 17H00 the problem starts, but still it is not fixed. Case no is: ********** 8</p>