IPhone 7plus Boot Loop Issue/Mic

My IPhone 7 Plus witch I've had for almost two year out of no where started bugging out badly.

Mid way through my day my 7plus started to flip out, Sri would just open and not respond. I tried making a call and it blacked out the speaker button and put the call on speaker, mic wasn't working. I went into voice memo and it says no audio devices found. So I restarted the phone and it didn't do anything. Later that week my phone still not working, I called apple and the lady told me to restore my phone which just wasted my time it didn't fix anything. So I called again and some other lady ran a test and told me, I didn't have apple care then transferred me to her boss, He basically told me to have a nice day you didn't buy apple care, take it to a store they will give you an estimate.

I'm asking on here if any others have the same issue or ones like mine with there 7plus. If so how do you get about replacing it. I need to get a fix soon I'm still not able to call or receive calls few weeks later.

Thank you for your time.