Hi my name is ***** ***** I will be the expert working with you today to help and resolve the problem you have posted.
I am sorry to know that you are facing problem with your phone let me know the make and model.
Backup your contacts, apps and photos on an external sd card and then we can perform a factory reset which will wipe off the phone and will become like a brand new phone.
once the phone is backed up its data and then follow the factory reset then no one can remote connect after that.
sd Card is the memory card installed on your phone for data storage which can be taken out as well. Yes you can backup your phone after you connect it to your mac and backup entire data with Itunes.
I hope I've provided the information you were seeking. If you have any question feel free to ask. Please provide a rating by clicking on the stars on top of this page and hit submit. Feel free to ask or reply me so that i can continue to help you answer you question further. Thank you.
do not install unnecessary apps and try to keep you phone clean from data which has been used and not required remove them try to clear the cache.
Is there anything else i may help you with?