Syrian Jamming of Lebanese Phone Networks?

This is not the first time this happens with me. I called Alfa about it before and they blamed my phone. So now it happened with my iPhone 4S (it previously happened with my iPhone 4) the moment I reached home in the North. A telecom engineer told me it couldn’t be my phone and this is illegal.

I have no idea how something like this is possible. I’m well off the Syrian-Lebanese border so how can I get Syriatel reception all the way on the coast?

It also sticks around for a good 30 minutes unless you force your phone to switch carriers. That also doesn’t always work.

The interesting thing is that if I switch simcards to the Syrian MTN one I got when I visited, it doesn’t work. It’s only with Alfa. Anyone with MTC having this as well? And can anyone explain how such a thing is possible?