Learn English – Difference between “believe in” and “believe”

Existing comments have clarified that it should be 'getting in touch with' or 'contacting'.
'Contacting with' doesn't work, though 'getting in contact with' is possible - I just wouldn't use it in either of the above structures.

I would also change the 'thanks'..

'getting in touch' is informal, so the structure

"Thanks for getting in touch with us"

works perfectly well.

On the other hand 'contacting us' is much more formal & I would prefer to see it book-ended with 'Thank you'

"Thank you for contacting us"

Our basement flooded due to the rain.
We rescheduled the concert on account of the rain.

There is (subtle) difference between those two sentences.

The rain actually caused the flooding of our basement. However, the rain did not physically influence the planning of the concert: we rescheduled it, not the rain.

In many cases, the difference will be so subtle that even native speakers may substitute one for the other.In general, though, I would advise to use on account of when an action or decision is influenced by something, and due to when something is caused by something.