Terrible Network

It's been months now experiencing network problems from cell c. I can barely access the net even though i do get 3g H+ but still i can't do anything. Also the voice calls now are getting worse, at first i thought it was my phone but i changed sim cards to put another network and it worked fine. I have two contracts with cell c, one for data and one for my s4, i had three before bt because i keep complaining and no one seems to value me as a customer i am slowly bt surely moving away from cell c. I get 1 gig per month on my s4 and to show how pathetic it is of late i stil have my 1gig from last month i now have to 2gig that i cant do anything with. i have to go to town to access the net. You where at 1 point my fav network provider.. you where the 1st to have 3G coverage in my area and you where the cheapest at the time but now you are the absolute worst.. i now have a data contract with the other provider, thats after not renewing my other expired data contract i had with you and i am getting excellent internet speeds. FYI i am due for an upgrade in june for my s4 bt if things dnt improve i am not going to upgrade and wil be canceling the contract. Plus your s6 prices r ridiculous!