@Koonlay, I saw your last post in my email alerts, but it has not appeared in the forum for some reason. I'll quote it:
What if I'm willing to pay for the cost of servicing even if the device is under warranty? I won't mind the cost. It's better done by paying extra than have a phone you can't use.
If the repairs will be done in Nigeria, then I'm willing to pay in order to have my device back. Please help?
It's likely that there are local non-Apple shops in Nigeria that repair iPhones. One of them may be your best bet. I believe the WiFi chip can be replaced, and it is a standard part. It will void your warranty, but the warranty isn't that useful to you anyway.