If you have no success with the contacts you've mentioned, you can get
in touch with ourselves
is arguably grammatical and idiomatic, but uses 'ourselves' as an emphatic rather than a reflexive pronoun. This article at GrammarMonster explains what emphatic pronouns are and how they are usually used.
As to the particular usage here, without an accompanying personal pronoun or noun, a usage note at AHDEL reads:
Usage Note: The -self pronouns, such as myself, yourselves, and
herself, are sometimes used as emphatic substitutes for personal
pronouns, as in
He was an enthusiastic fisherman like myself.
The practice is particularly common in compound phrases:
The boss asked John and myself to give a brief presentation.
Although these usages have been common in the writing of reputable
authors for several centuries, they may not sit well with many readers
today. A majority of the Usage Panel dislikes them, though resistance
has been eroding over the years.
An article by Ben Zimmer at Visual Thesaurus contains:
Part of the problem is that myself gets plugged in as a replacement
for I or me in many different ways, and people's judgments of
their acceptability may vary widely....
You can judge for yourself which uses of myself sound acceptable or
unacceptable, and which fall in a gray area somewhere in between.
Personally, I don't mind myself too much when it appears at the end of
a list of names, as in Safire's "Price, Buchanan, and myself" or
Boswell's "Sir Joshua Reynolds, Dr. Burney, Dr. Johnson, and myself."
(Linguists call these "coordinate structures.") It also sounds
relatively fine to me when the speaker or writer is making a
comparison to someone or something else, especially after than, as
when John McCain speaks of "serving a cause greater than myself."
Personally, I find He was an enthusiastic fisherman like myself. totally acceptable, and the first sentence in this answer at least as good as the 'with us' version (I feel emphasis is required to mark the unexpected suggested alternative).
However, using 'get in touch with ourselves' where the unmarked 'get in touch with us' is required is ridiculously bombastic:
*/?? 'We are Scan-Tecs. You can get in touch with ourselves in the following ways: ...'