The industry saw its best improvement -- up 30 percent -- in the area of communications, according to the survey. According to The Customer Respect Group, telecoms scored 5.9 in the area of communications, higher than the 4.9 average rating seen in a range of other industries. Although the study found that 13 percent of e-mail questions were still ignored, the quality of the responses has improved since the last report -- especially among companies in the wireless sector.

MVNOs fared worse, with that sector ignoring 25 percent of all e-mail questions and being slow to respond to those questions that were answered, according to Golesworthy. Wireless companies, in contrast, responded to almost every e-mail, with two-thirds of the companies responding within one day, he said. The best performers in that area included Verizon Wireless, CenturyTel, T-Mobile and Sprint, he said.

In the area of trust, wireless companies scored worse than traditional telecoms. Overall, 22 percent of the companies studied still market personal data to outside firms without the explicit permission of the customer, according to the survey. The industry is also most likely to reuse personal data, with 73 percent of the companies using information to market additional products. While "opt-in" options are slowly being accepted in other industries, fewer than half of the telecommunications companies offer that kind of customer control over their data.

"In terms of reuse of data, particularly in the wireless and cable industry, there's a lot more cross marketing going on," Golesworthy said. "There's less sharing with other companies but... they're trying to maximize what they can get out of their customers."

The top-scoring telecoms in the U.S. were Verizon Wireless, with a score of 8.5: CenturyTel, 8.2: T-Mobile, 7.1; Sprint, 7.0; and Qwest, with a score of 6.8.