S&C MODULE 8M5T-19C112-AH - Voice Control is Still in German????

That's right but no fault by the Radio/Navi but the version of the S&C module itself. Only Modules starting with built year 2010 have mutiple languages that can be selected via menu. Modules with part numbers beginning with 7, 8 and 9 are working in one fixed language only. The last but one digit denotes the language of the module, A for english, B for german, C for french and so on. No way to change that (other than swapping the module) or to use more than one language.

In your case, something is wrong with the supposedly english module. Where did you get it from? Is it possible that the part number is a fake?

Here you can find the 3 last S&C update packages: http://www.motor-talk.de/forum/altes-audiosystem-update-t5314658.html?#post43836069

If you download the S&C update files, you'll find 2 files related to included language always, e.g. 8M5T-14D511-A*.bvc + 8M5T-14D511-A*.vbf for english, *-B*.bvc + *-B*.vbf for german and so on.
You may try the upgrade to the oldest package from 11/2011 first. Then the following should happen:
a) if installed SW at your module is a german Version, the module will install the 2 german files *-Bx.*
b) if installed SW at your module is the english Version, the module will install the 2 english files *-Ax.*

If a) happens, you may try renaming the 2 english files from next higher SW version 4/2012 *-Ax.* to *-Bx* (only changing letter A to B) and update.
Module should update then the B-files which containing english content now.

If b) happens you have solved problem already and you can update to latest version normaly.

Upgrade is possible to higher versions only, that's why its important to start with oldest Update package.

If this is working indeed I don't know. You may try it, but w/o any guarantee that it is working and not damaging the module. I would expect that it is not possible to damage the module by doing so, but you never knows.

I expect that you have already latest SW version at your module. Then you get a message "version already installed, no update done" or similar.
Because there are not much possibilities to have such module you have. Probably it was manipulated same way I described.
Step 1) to try normal update with oldest package from 11/2011 there is not much risk as you do no manipulation (beside normal risk with every update - please follow the update instuction from link above).
Probably the label is correct and b) happens.

Since any update to an older or identical version will fail, there is nothing more to do with that particular module. Your only hope can be to find another module, problably in the desired language from the start.