Inconsistent internet connection

*** MTN!!! I live in a small town with very few options when it comes to internet connection. We have no fibre connection here an rely on wireless internet. I work 2 jobs. One full-time during the day and one at night from home. I have been using Rain as my service provider up to now but they do not offer LTE faster than 10Mbps per second but at least they are consistent at that speed. I decided to move to MTN fixed LTE uncapped 30Mbps and was forced to buy a specific LTE router which cost me R2000. When I started using 4 days ago I got 30+ Mbps and was very happy with that. Tonight I get home from my day job and find that I only get between 5 and 8 Mbps wich is worse than my Rain connection. Luckily I did not take the MTN fixed LTE on contract and paid cash for my router. I also have not canceled my Rain subscription yet, thank goodness for that. One would think that a company like MTN would be able to render a good consistent service. NOT IMPRESSED AT ALL!!!