The fragmentation of old and even new media channels these days makes it difficult for companies to communicate effectivey. And following the further fragmented dialogue caused by these messages is an issue of exponential difficulty beyond that!
So how to you ensure a customer has a complete view of your own company?
In my opinion you can't fully right now, because as soon as you use different channels for customer communication you loose a certain rigour. As for controlling which channel customers use.... "forgeddaboutit". As I said yesterday, its all about channel relevancy.
Lets be frank, customers don't care if your call-centre/website/branch is out-sourced or have different staff training processes now...
...To them it is all the same company, regardless of channel!
But you can help yourself:
How often do you see a press release with no URL to additonal information of supporting data?
(Answer: still too much!). Online date should link to each other, it joins a users thinking with your efforts and was the purpose of the WWW in the first place. Don't forget that links between your different online submissions can help in your Search Engine Optimisation efforts as well.
2. Be consistent across all channels:
As any Marketing or PR manual will tell you, you must make sure you give the same message as often as possible. Channel mis-match confuses people and this is even more important digitally (where inconsistencies can turn up in the same Google search). Consider a quality process for all your externally-bound content. Have a corporate-wide terminology database, especially if you translate content (and make sure ALL translation companies have access to this source). Give call-centre/customer service staff the same information you give everyone else and be prepared to manage the exceptions / issues carefully, noting what those exceptions are (product, brand, circumstance, etc.).
There's far more information from Mr Bob Liodice on the subject than I could ever provide.
3. Track your messaging
Monitor what gets said across the web and who says it. Social Media monitoring solutions are increasing in their ability to detect sentiment and can be inexpensive to implement quickly.