A couple of days back I had this conversation. The question was very clear and, given that everyone has their own special and thereafter the common horror stories of interaction, I figured that I could think about the answer I had provided. So, here's a small list of what I think could be better.

• Better documentation. Most companies/organizations do a very bad job with keeping the documentation updated or, even maintaining a FAQ at any place. For example, if you look at the ISPs, they generally end up receiving incoming calls which can probably fall under the buckets like - billing, network connections, services. And yet, they don't really keep any documentation available in public which can help self diagnose. The computer equipment manufacturers seem to have found out the benefit of this, the service providers haven't
• The lack of documentation theory is further strengthened when you call in and get someone on the other side (after umpteen rounds of muzak and "your call is important to us") who will end up doing a stock template response. I've had, in recent times, complained to Airtel about 3G services not working while voice services are active and, in return have received a sales patter about how robust Airtel's network is.
• Then of course there is the tendency to distrust the customer. Airtel DTH will practically tell you to your face that whatever your complaint is, it is not true. Airtel (cell phone) are a bit more subtle, they'll ask you to provide information that is odd viz. your billing cycle, when you complain about a VAS bit not working.
• Inarticulate agents. Irrespective of whether I am calling in from Pune or, from Kolkata, I'll end up with someone who has trouble understanding very basic English and has a tendency to lapse into the vernacular. Even if I choose not to speak in the local language. This could be a result of outsourcing to the cheapest service provider but it does suck when you have to take more time than required and break up your problem just so that the person can lodge in the proper complaint.
• If my call is important to you then ensure that I am not on hold for a long time. The IVRs have odd loops and, more often than not end up keeping you online (and, paying for the call) even though you'd wish that you can read up somewhere what could be wrong. I've timed my interactions with the vendors for a period of 6 months now. Here are the results as average (I've done more than 10 calls for each vendor around this time):
  • Airtel DTH : 11 minutes before I get a human (calling between 0900 and 2000). 8 minutes when the time is beyond that range.
  • Airtel (cell phone) : 9 minutes before I get a human (calling between 0900 and 2000). 15 minutes when the time is beyond that range.
  • Tata Indicom Broadband : 10 minutes before I get a human (calling between 0900 and 2000). 15 minutes when the time is beyond that range.
  • Tata Teleservices : 8 minutes before I get a human (calling between 0900 and 2000). 5 minutes when the time is beyond that range.
  • ICICI Bank : 12 minutes before I get a human (calling between 0900 and 2000). 10 minutes when the time is beyond that range.

Then of course there are times when you get geniunely hilarious responses (this was in a customer support email addressed to me) like this :

Dear Vijay  Kamble,

Ref: Email dated 23-08-2011, requesting for 3G settings  on your airtel mobile number <edited out>.
Please ignore the previous mail.
Thank you for your email to airtel and the opportunity to assist you.
We regret to inform you that , we are unable to mail the settings that will enable 3G on your airtel mobile number <edited out>, so we request you to contact 12134 .
We hope that this response has addressed your query  suitably.  
Please do write in for any further  assistance.

Yours Sincerely, 

$USERNAME$ 
Customer Care 
Bharti Airtel Limited

Md. Quamrul H