Throttled internet for the past 2 months.

Throttled internet for the past 3 months. Been struggling with speeds of 0.80 mbps 800 ping on my home LTE package strange thing is after 11 pm it shoots up to 20-30 mbps 300ping. Contacted MTN customer service and they told to send to ***.. I cant send a mail to this address u can only send via internal. I sure as hell do not and will not work for MTN. Still waiting reply