Hi
I just did that. I created a partial view called _CustomerService.cshtml under folder Views\Common (either in the web application root view folder or in your custom theme's view folder).
Here's mine for example:
Views/Common/_CustomerService.cshtml
<div class="block block-info">
<div class="title" id="atencioncliente">
Customer Service
</div>
<div class="clear">
</div>
<div class="listbox">
<table width="100%">
<tr>
<td>Phone</td>
<td><strong>917362630</strong></td>
</tr>
<tr>
<td>Twitter</td>
<td><a href="http://twitter.com/xxx">Our twitter</a></td>
</tr>
<tr>
<td>Facebook</td>
<td><a href="http://www.facebook.com/xxxx">Our facebook page</a></td>
</tr>
</table>
</div>
</div>
Then, if you want it added on every page, you must add it to _ColumnsTwo.cshtml and _ColumnsThree.cshtml, basically the layouts your current theme is using (it may be also one of the fluid layouts).
You can then open those files and put this code to render the partial in the spot you want it to appear:
@Html.Action("MiniShoppingCart", "ShoppingCart")
<div class="clear">
</div>
@Html.Partial("../Common/_CustomerService")
This is from _ColumnsThree.cshtml, near the end of the file (~ line 75).
Personally I chose to put it next to the mini shopping cart, either right side in 3-cols or left side in 2-cols.
You may notice the path to the partial is not using the standard ~/Views/Common/xxxx approach. It's not working for me that way, even with nop 2.20 so I switched to relative paths instead.
Hope it helps,
C