Grudges take up brain capacity and prevent us from performing at our very best. What we focus our minds upon grows; this is true of hatred too. Therefore, it is impossible to truly achieve great things for ourselves when we have a lot of our energetic capacity tied up in negativity.
Remember that forgiveness is primarily for YOU. It free up your energy tremendously. So forgive all grudges, no matter how old they may be, and seek reconciliation. If you find this hard, begin with the easiest ones first. Then gradually work up to the harder ones.
All the years you have waited for them to "make it up to you" and all the energy you expended trying to make them change (or make them pay) kept the old wounds from healing and gave pain from the past free rein to shape and even damage your life.
And still they may not have changed.
Nothing you have done has made them change.
Indeed, they may never change. Inner peace is found by changing yourself, not the people who hurt you.