flatbusher – I really feel for you. I think you are correct that there are people who ask mechila because they know they should but as I tell my children when they would apologize for things, unless you are going to try to do differently next time it is not a sincere apology. And from everything I have learned, you have no obligation to forgive, but even when you do, you don’t have to feel kind toward them or trust them. Mechila is to right a wrong, not clear a conscience.
Someone who caused immense pain to me and my family has yet to apologize, and continues on an ongoing basis to perpetuate the wrongdoing. (similar to pulling business away from a certain vendor for dishonest reasons, feeling really bad about it, but continuing to shop elsewhere anyway) Even if they ever asked for mechila (which is doubtful), I don’t think I could ever forgive them while they continue with the same hurtful behaviors.
You are worth too much to allow people to hurt you and mechanically forgive them. And if they don’t want “that type of time period”, then let them be more careful next time. Forgive them when you are ready, but meanwhile you can feel sorry for them that they weren’t more sensitive, learn from their mistake, and be wary of them in the future.
This is just based of that which I have learned, I hope it addresses your question.