Slower Internet - slower then 2G

I have used Rain for a while a year in Centurion and then I moved and got free Wifi but then had to move again and I got Rain again in Roodepoort, in Roodepoort I was getting 10mb/s to start but then it started slowing down after 4 months was down to 2.5mb/s. Then I moved to Margate and I checked to see if the area I was going to was in coverage and it was 2 towers 1 is 0.85km away and the other is 0.98km away (according to their coverage map on their site). my speed was even slower, has not been faster then 1.8mb/s for the last 2 months, and for the last 4 days its been 0.4mb/s. I have complained and the response I got was sorry they need to upgrade their system as their is to many users in a small town with 5 towers really???????????????? but you happy to keep charging R479 but can not deliver as advertised. I down graded to the 19 hour package because it is meant to be faster and if it does not improve I'm moving over to Vox at R50 more with a faster speed. the service is **** and if anyone wants to use Rain don't waste your time and money. Rain cant deliver 4G network and speed.