You are saying that somehow someone sends texts from your phone ?
I'm unsure what is possible these days but to me that sounds unlikely but if it happened it would be your phone doing the sending. Why would any mobile they owned or didn't own, show up ?
On the other hand if they are managing to send on their mobile and convince the service provider it came from yours, I reckon they'd have to have a skilled person on the inside to arrange it. If fact I'd have thought that impossible.
Otherwise maybe you could describe the issue you are asking about in other words ?