no we will not mount a Slimline dish to a brick wall. Its either going to be installed on the roof, or you will need to pay the installer (price varies per tech) to put a pole mount in for you. You can refer to this page for more information.
http://support.directv.com/app/answers/detail/a_id/1489/~/custom-install-charges
Generally speaking you are looking at about a 75-150usd cash upcharge for the pole to be installed. A directv free professional basic install covers the dish being mounted to the roof, and a hole drilled through an exterior wall, or floor into a basement for the lines to be run through. Literally anything else is custom and "CAN" be billed to you by the installer if they wish. A pole mount is only covered under basic installation if there is no valid line of sight from your roof line do to trees. Since this is per your request, it is custom.
Back ontopic, mounting the dish to a brick wall is not an acceptable mounting method in any circumstance any longer. You can attempt to "bribe" the installer however you see fit, to get the install done "to your standards" but I recommend against the brick wall personally. Plus no installer is going to carry the proper supplies to "properly" mount to brick, as were not supposed to do it in the first place, so it would most likely require a trip to a lowes or homedepot on the part of the installer and a bill to you for custom supplies.
That being said, not all installers are prepared for pole mounts either. You may be rescheduled to accomidate this, your best bet is to allow the install on the roof, or to try to have a csr add a note to the order to bring a pole and cement for a ground mount.
Again all this being said, this is something you will need to pay the installer cash to do. Some installers accept credit via square or paypal readers on smart phones, most don't, none should accept checks. Its just business, nothing personal meant.