Slow LTE

I had Telkom LTE installed middle 2016 and had brilliant speed >70mbps UNTIL Oct/Nov 2016 when the speed fell drastically <5mbps. I phoned 081180 and they said they would check it out. 8 March 2017 relogged a fault, this time using FB Messenger and got a case nr ********** 6 assigned to my problem. Since then I have only been receiving apologies and empty promises of escalation. I post to messenger everytime the line is virtually useless <1mbps and still I get apologies and empty promises of escalation and "our team is working on the issue". Bulldust, how can it go from >70mbps down to <1mbps and nobody has even visited my house, except that one time when a consultant came and found that my self purchased poynting antennae will not connect to my your closest tower, instead it connects to a further tower. This bloke said he would escalate my case, once again nothing has been done! When can I expect to get better speeds than <5mbps as you promise speeds upto 90mbps?