I just wanted to post this because this something that I personally searched for recently.
I wrote a goodwill letter asking them to remove the last two late payments and the reason why I was late. It took a little more than a month but I received two letters (one for me and one for my spouse) stating they would update their records and to allow 30-60 days to reflect on credit reports. However, as of this morning- the update was already showing AND they removed 6 MONTHS and not just two.
Even though we had only missed one payment- we could never come up with enough extra to pay the missed payment + current due. We did finally get caught up but not before our credit showed many 30 days late.
Hope this helps someone interested.