Choice of さしあげる in お電話さしあげる


I'm a bit confused by the usage of さしあげる in this sentence from Kanji in
Context:

ただ今、来客中ですので、後ほどこちらからお電話さしあげます。 We have a guest at the moment, so we'll call
you later.

To me, お電話いたします or even お電話いたしてさしあげます are more grammatical. Maybe it's really
お電話(を)さしあげます? (I'll give you a call).




[差]{さ}し[上]{あ}げる is [謙譲語]{けんじょうご} for words like あげる and やる, as well as してあげる.
By itself it means _to give_ (with a sense of great respect), and as a
subsidiary verb ([補]{ほ}[助]{じょ}[動]{どう}[詞]{し}), it adds a great sense of respect
(for the person receiving the action) to the verb it is helping.

[致]{いた}す is basically 謙譲語 for する.

`電話（を）する（いたす）` can be thought of as: "to call".

`電話（を）してあげる（さしあげる）` can be thought of as: "to give a call".

In the sentence, the callee is telling the caller to expect a call back. This
creates a sense of "waiting"; so, instead of just "calling", the person will "
_give_ a call back" (i.e., 電話をしてあげる). However, in business situations 謙譲語 is
preferred on the phone. So, the frank-sounding `してあげる` becomes `差し上げる`.

As to `お電話（を）いたしてさしあげます`, converting back from 謙譲語 would yield `電話（を）してしてあげる`,
which is blatantly incorrect.




お電話差し上げる reduced an を but it's correct in a grammatical sense.

To keep it simple, 「差し上げる」 is the 謙譲語 of 「やる」.

In 「お電話を差し上げる」, 「差し上げる」 is the predicate, thus it is a polite way to say
「お電話をやる」.

In 「お電話をして差し上げる」, 「する」 is the predicate, thus it's **_NOT POLITE AT ALL_**.
The sentence means 「電話をして」 + 「やる」. It's really bad to say 「してやる」.

「お電話を差し上げる」 would imply that the person who's going to receive that call is
**_expecting to get that call_**.

So I personally believe it's simpler, more direct and more polite to say
「お電話致します」「お電話をさせていただきます」.

Hope this helps!

