Is there a number I can call to change my straight talk iPhone 5 towers?

You can try calling your service provider and tell them about the issues you are facing. Cell tower assignments are not customer choices.
Mar 23, 2015
Bad system. Same as what Verizon rep told me - "It's the tower you got signed up on," explaining why Straight Talk's TV ads claiming 4G LTE couldn't apply to me. It's all a very bad system. They've got us where they want us.