How can I regain speaker functionality on my iPhone after suspected remote control hacking?

I've heard it said that Iphone can't be controlled remotely..I was aware in each of four times i have been hacked this past year. They were all related I believe so that can explain the frequency. I believe screen mirroring at someone's house to play music or videos. Once in I found a bunch of stuff downloaded within the QR reader app that I deleted and I found that there was an IHome app downloaded with contacts listed as "homeowners" (myself included). When I deleted the contacts associated with the app, its app icon shot across the page and revealed my contacts app. I found I had duplicate contact apps so I deleted them and reinstalled. Phone number related to the hackers: once I deleted them i stopped receiving text messages from them. Every now and again i found myself with another bit of evidence to prove I was "hacked". Texts from a multitude of numbers but only apparent if assigned a contact name> Amazing what I witnessed someone achieved in what I went through with my iphone. Many trips to Apple store, you name it. I finally feel mostly in control, i just can't seem to regain use of my speaker during phone calls, everything else it sounds great. I have had diagnostics run on it recently and it showed no damage related to speaker whatsoever. I also ran the most recent update as well and I think that helped. Apple admitted hackers found a way in on the previous update. I think it's time to stop questioning if Iphone can be hacked and start accepting that it can and investigate individual reports. I gained a wealth of experience that I wouldn't have had i not experienced it so many times. Would love to share knowledge I gained in attempts to stop it from occuring to anyone else.

[Re-Titled by Moderator]