Why is my bluetooth not working?

My bluetooth has recently gone out on me. I can’t put an exact date on when this problem began to occur but along with this my wifi has been quite problematic as well. When I attempt to try to connect to someone’s wifi, the signal with either be extremely weak or my phone will not pull it up, acting as if there are no networks to join when everyone around me can connect without any problems. My phone does however still connect to my home wifi and occasionally some grocery stores or restaurants’ wifi. We have brought my iPhone up to the genius bar at apple and they have told me that it is a hardware problem. They said they were unable to to fix it and that i would have to buy a new phone but I only bought my phone a little over a year ago and I feel as if they only told me this so I would have to buy another phone so they can make profit from me. My phone is a Silver 6s (iPhone obviously) and my wifi and bluetooth used to work just fine. I can still connect to some bluetooth speakers but my phone and the speaker must be touching in order to connect and after a foot or more apart for each other, they disconnect. I’ve tried connecting to various speakers with and without my case so I know it’s just my phone; I just do not know why. I also recently received an apple watch as a gift for valentine’s day but the watch does not do me much good considering the fact that I can’t even get my phone to connect. Is there any way I have someone fix this or fix it myself without having to buy a new phone, considering mine is fairly new? I understand that it would be time for a new phone sooner or later I would just rather it be later rather than sooner. Plus it doesn’t hurt to ask.. any advice would be of much help!