I used to work customer service - believe me, I hated trying to sell customers things just as much as, if not more than, they hated having to listen to it and repeatedly tell me "No." But, if I my call got randomly pulled by QA and I hadn't made an attempt to sell, I would be reprimanded, up to being fired. I know it stinks having to listen to the sales spiel.
It took a lot of gumption (and one heck of a thick skin) to attempt to sell more products to unhappy customers. That's one of the biggest reasons why I quit the call center and went back to churning out grub for a living for the time being. The vendor I worked for, and the company to which the vendor was contracted, was ruthless. They would force us to try to sell DSL internet to anyone who was in an area that was available for it - and so many of my calls came from people on fixed incomes who didn't even own a computer, smartphone, or gaming system, and they wanted me to try to sell them DSL internet!
Sigh. I only lasted a few months there because I just couldn't be that heartless - and since I was working for a vendor and not for the company itself, I was very limited in what I was actually able to do to help the customers. If I could have actually fixed a lot of the issues that came onto my line, it might have been better, but nope. And talk about misdirected calls - people got stuck in phone tree hell with this particular company. Someone who had already been transferred three times would end up on my line, only to find out that I couldn't do anything for them and I'd have to transfer them again. I felt so bad for so many of these people. If I can sound conceited for a minute, lol, I think maybe I had too much of a heart to work there. For every jerk that came on my line, there was also someone who had a problem who was being nice and I couldn't help them because of my limited powers as a vendor employee and it just made me feel awful. It was so depressing.
Sorry, that kind of turned into me talking about how terrible it was to be on the other end of the line, lol.
I do urge you though, if they invite you take a survey at the end of the call grading their service, and you have a couple extra minutes, do it.
It directly affects that agent, so if they weren't helpful and weren't a good customer service rep, it lets their supervisors know it, and if they are helpful, they sometimes get little perks for having good scores on the surveys. I spent a good chunk of my time at the call center being exempt from mandatory ten-hour Mondays because I had good feedback from the surveys!
Some places give the agents bonuses for good scores, or other smaller prizes. Either way, it really does the agent a favor - it lets them know what they're doing wrong, or lets them know that they're doing things right. Of course you don't have to do it, but if the agent was exceptionally horrible/rude or exceptionally awesome, it does help to do the survey because it lets their superiors know.
I don't mind holding, as PastryGoddess said, as long as I'm holding for a rep. I just don't know what to do when I'm holding because I don't want to be distracted when they finally do come on the line, or worse, in the bathroom, lol. (I have this thing about being on the phone while using the bathroom, especially with a business call.)
I do the surveys on receipts - mainly because I want a chance to win some money, lol, but also because I want the company to get my feedback.