Rain bad signal reception

Im living in Sasolburg, where Rain shows I am supposed to have have full 4G signal, and Ive got the 4G unlimited service with them, up to 10mbps. When I do a speed test, I rarely get to do the test because of such bad reception to my router from a Rain tower just 1.8km away from me. When I do get to test, my internet speed is give or take ****bps or slower. I have sent mails and called them with no luck of me even seeing any action from their side. Other clients in my area does not have this problem.