Looking on the internet deeply has found these results:

I will get back to you is the most popular phrase on the web.

I will get back with you 11,530,000 results on the web	I will get back to you 122,200,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
And I will get back to you with what I find as soon as I can. I will get back into it, I Let me check the details and I will get back to you with the results of my enquiries. Well, I will get back to the outer layer... There's no guarantee Reycraft will get back with those lungs in time. However, I will get back to you with further information, if you do not mind, Mrs Doyle, and I apologise for not being able to give you a more precise response. I will get back to you with the name you wanted shortly. I will get back at you with some shiny new developments, okay?	Let me check the details and I will get back to you with the results of my enquiries. Well, I got to be somewhere, but I will get back to you. However, I will get back to you with further information, if you do not mind, Mrs Doyle, and I apologise for not being able to give you a more precise response. I will get back to you on the detail when I have had a chance to study the matter. I will get back to you with the name you wanted shortly. I will get back to you on all of this later. There is an issue; it needs to be looked at, it is being looked at, and I will get back to you as soon as possible. I will get back to you very soon.

I will get back with you

11,530,000 results on the web

I will get back to you

122,200,000 results on the web

More popular!

And I will get back to you with what I find as soon as I can.
I will get back into it, I
Let me check the details and I will get back to you with the results of my enquiries.
Well, I will get back to the outer layer...
There's no guarantee Reycraft will get back with those lungs in time.
However, I will get back to you with further information, if you do not mind, Mrs Doyle, and I apologise for not being able to give you a more precise response.
I will get back to you with the name you wanted shortly.
I will get back at you with some shiny new developments, okay?

Let me check the details and I will get back to you with the results of my enquiries.
Well, I got to be somewhere, but I will get back to you.
However, I will get back to you with further information, if you do not mind, Mrs Doyle, and I apologise for not being able to give you a more precise response.
I will get back to you on the detail when I have had a chance to study the matter.
I will get back to you with the name you wanted shortly.
I will get back to you on all of this later.
There is an issue; it needs to be looked at, it is being looked at, and I will get back to you as soon as possible.
I will get back to you very soon.