3. A frank talk
Sometimes, closure is what is needed. So do them a favour of having a sit down to reiterate again that you meant it when you said you were no longer interested in the relationship.
Give reasons why, and be very firm about it. Don’t be ambiguous in any way, you don’t want to have them thinking a second chance might be on the horizon.
Remind them of why it didn’t work and encourage them to move on.
