Q: My iPhone 5s has been stuck searching for a cellular network since I did the last upgrade to ios 9.2.1, what do I do? There's been no water interaction or falls or pressure application on the iPhone so I have total doubt it's a hardware issue

My iPhone 5s has been stuck searching for a cellular network since I did the last upgrade to ios 9.2.1, what do I do? There's been no water interaction or falls or pressure application on the iPhone so I have total doubt it's a hardware issue but rather a bug from the iOS upgrade. I did an OTA upgrade. The problem hasn't occurred before, I've done a restore from my phone but not the itunes software mainly bcos it has to download the ios again which I haven't the internet capability atm unless I dunno I go out to an Internet cafe or something. According to my research people blame it on the baseband chip which is scary bcos there's no apple shop here in Accra,Ghana well they're just retailers over here so it's either I let some technical squad not from Apple open it up or I'll have to go through the pain of sending it in to the apple tech team in the US which will also be costly since my warranty is expired.

Which reminds me after I did the erasing of all data and settings on the phone I'm stuck at the activation window and it's refusing to activate OTA and via itunes software telling me the server can't be reached now try again and it's been days and certainly not my internet connection too plus Apple activation services have been running fine for days now. Bottomline my phone is like a brick now since i can't even use it as an iPod. Need help big time.