Poor Service( settled account: Paid up letter and ITC update

I am an FNB client for years, but now i'm puzzled with the poor service I received. I had personal loan with them which was settled end of April, I then phoned to request paid-up letter and I was told refund must be done first since they noticed that I over paid. I made follow-up 3 times but nothing was done. I then logged a complain on their website and I received a call from the lady by the name of Zianda who promised that refund will be done and paid up letter will be done ASAP, money was refunded but there was no further communication. when I check my ITC record it still show that I still owe their loan and till today letter not send. I then phoned and consultant (Jennifer) a letter which is not stamped or signed and she said I can only get proper letter after 26 days, which to my knowledge it will be 48 days since its already 22 days after I settled their account.