AN ACCOUNT KEPT ACTIVE AFTER PRESCRIPTION

I have an account with NEDBANK that has prescribed, i wrote to them directly to raise prescription as a defense as i had not acknowledged this debt in payment or promise of payment in the last 3 consecutive years and no summons were sent in the last 3 consecutive years. NEDBANK is not doing right by me as this is hampering a lot and my life is on hold because of this. It is the law that accounts come off after 3 consecutive years and they are not following this law