Disable calls and texts on Samsung galaxy S4? Stalker?

I still have an S4 so if anyone has any information on those that would be great. If I block text messages they just get put in the spam folder, I can STILL see their texts and it still takes up my phone space so I am assuming. They will send about 100 messages a day if I don't respond and they are so draining deleting and deleting over and over.

I also reject calls, but the number still rings once so I know it is them. He has a variety of mental issues, hurts people to the point of almost killing them and refuses to get help. He undermines my feelings and even went as far as to insult my parents. He thinks in his own mind that we are friends again and keeps spamming my folder with his problems and anger rants against me when I don't respond and I just want this loser out of my life.

Any really trustworthy apps I can download to avoid this problem? I can't change my phone number or permanently block his number because my parents don't want me wasting the money. They completely understand what he is doing to me but I would feel so much more at ease if he was completely gone.

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