German phrase
Ich melde mich per ~ bis ~.
Meaning
I will get in touch via ___ by ___
When to use it
It promises contact by a date. It is a polite way to state how and when you will follow up.
Example dialogue
Ich melde mich per Telefon bis Ende der Woche.
I will get in touch by phone by the end of the week.
Vielen Dank, das wäre sehr hilfreich.
Thank you very much. That would be very helpful.