Its so rare to receive exemplary customer service in any industry...
So, when I do receive it I make sure to praise them. Often ill compliment them on their businesses fb page.
And, if its restaurant, taxi etc. I also give a generous tip WITH big compliment.
Heres an amazing story that happened to me around Christmas;
I called the Medicaid number to give them my new mailing address. The man replied: "I see here you have $60 in unused benefits. I'll tell you what items are in the catalog so you can place an order!
(Things like heating pads, or otc medications!)
I told him thats an amazing surprise Christmas present!