I got the credit, but I had to fight for it, and I'm not sure that I would have if I had been able to access my
MDE magicband page to change to a free color or if I had been informed at some point that my order was out of stock (I did get the "order delayed" email last week, but today when she looked it up she said it had been switched over to gray bands). It was really pointing out that I would happily take an in stock free solid color if I could get past the 7 dwarfs technical error page to order them that finally got them to give me the credit - until that point they told me that I could switch from gray to an in stock solid color on MDE (ignoring that I had already said I couldn't so that due to the 7 dwarfs error), take the gray ones, or pay full price to order new ones myself from Shop Disney. I think they may be sticking with the "out of stock, sorry" line for anybody who is actually able to switch to a free one now.
The number is 1-800-328-0327 if you want to try to get the credit. I haven't heard of anybody getting FPs, though.