payment letter

I made a settlement payment of a credit loan and they promised to give payment letter in 21 days, now it has been over four months. I have called them many times and got promised a letter every time I call till today nothing has changed. This is affecting my credit record and it has been a sad experience. I have spent more money calling them than the money I had owed them.<br> I'm sick of their empty promises and would never advice anyone to consider them.