[Date]

[Addressee]

Dear [Name]:

This is the third letter regarding the request for crediting 
my account. 

Enclosed are copies of previous letters, to avoid having 
to set forth the same information for you again. 
Unfortunately, this is becoming quite annoying by all of 
the late notices you have been sending in error. It would 
be greatly appreciated if someone would straighten out 
the problem that exists on your end. 

The difficulty you must have in maintaining all of your 
records is understandable.  If you would bring my 
correspondence to the attention of your credit manager, 
they may decide to suspend the mailing of these 
notices until this problem is resolved. 

Thank you. 

Very truly yours,