I spent 8 years doing customer service work over the phone in the continental USA.
The best place to start is to use their name. I was always impressed when someone addressed me by my name.
After that, express your gratitude directly, then ask them how you should proceed.
"Hey, [Name], you've gone above and beyond to help me and I want to make sure you're recognized for your effort. What's the best way for me to do that?"
Over time, my employer had several different acknowledgement mechanisms which had different weights attached. Some examples:
- Speaking to my supervisor
- Writing a letter to the site manager
- Completing an over-the-phone satisfaction survey
When I started in 2003, a physical letter carried the most weight. When I left the service floor, the phone survey carried the most weight as there were counts of how many 10s you received each month.
Now that I'm on to another career, when I receive good service (and bad) over the phone I ask to speak with the rep's supervisor. You can learn a lot about the company based on their response! Most of the time the supervisor is thrilled to have five minutes on the phone with someone who is happy to talk to you about something going right and that they will note the rep's file accordingly. Only twice have I spoken with a supervisor who has said the company literally has no mechanism for handling compliments and would I please stop wasting his time.
Social media interaction is going to be a bit different of course, but I wanted to illustrate the spectrum of response.
Another reason to ask is to make sure you're sending feedback to the right place. The service rep may be an employee of the company or may be a third-party contractor. If the person is in an offshore contact center working for a division within a larger company, a letter (postal or electronic) to the home office could be delayed for weeks or never routed to the proper location. This is especially true if you don't have the person's full name and location and they are part of a large staff.
One last consideration is there may well be a company policy regarding the acceptance of gifts. Some of my employers have allowed gifts under $25. Others make exceptions only for food items (e.g., cookies or a fruit basket). All of them have prohibited accepting gifts of alcohol.
As a former service rep, let me say thank you for your willingness to acknowledge a job well done.