How to link sentence better?

[pattywoo]

How to link sentence better?

For example:
If you do not want to leave a message in our telephone recording system, please contact us by post or email, or give us your comment at our department.

How to link "by post or email, or give us your comment at our department" in a better way?

[Andrew Whitehead]

"...contact us by post, email, or direct at our office"

[pattywoo]

Then is it correct to write like this:

"...please contact us by post, email or at our department."

[Andrew Whitehead]

Then is it correct to write like this:

"...please contact us by post, email or at our department."

That would be fine Patty, but put a comma after 'email'. The commas separate items in a list.

a, b, or c