Spam Bot infestation, please assist

Sorry, can't find anywhere else to request help for this, google showed me here.

I was sent a contact from an ex-friend...
It is spamming me 100 messages per second of nonsense. I tried deleting, blocking, reporting, muting but it still keeps spamming me and forcing the emotions through.
Also, i'm now unable to receive messages from other people nor groups. Have been told it's whats done when the individual wants to force you to delete your Line account...

Is there a solution?
Have no programming knowledge either.

Thanks