Evo Wingle Speed

My Evo Wingle Speed Is

Download Speed 5.74Mbps

Upload Speed 1.50

https://lh4.ggpht.com/ersRYyjcUKCaAWasDgXsnAW02yM3UPI5UwYYpZPblsC-8mEA2GBcWnoBnyQ7XDO8r_p1=s136

I have EVO Wingle with 4 signals. But my downloading speed is stuck to 0.45Mbps. I registered complaint to PTCL serveral time. They say that your are getting signals from two PTCL tower. So, thats why the speed is slow. What should I do to restrict my device to take signals from only one tower?

I have received up to 7Mbps download speed on Wingle, but only one time :D