A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

Note: 
The expression does not correlate in meaning with the
phrase get through to something—(Sport) manage to progress
as far as the last round in a competition, etc.: I was so excited
when I got through to the finals, but I think my mum was
even more pleased than me.
get through to someone • get through with
 someone
get through to someone —
1
. get in touch with smb. by tele-
phone: It is very rare that you will get through to the right
person on the first call. 2. succeed in being understood or
accepted by a person: Few teachers can get through to students
who don’t want to learn.
get through with someone —finish punishing or scolding a
person: When the teacher had got through with the class, they
felt very ashamed.
Note: 
Neither expression correlates in meaning with the phrase
get someone through
—(also: put someone through) 
1
. cause smb.
to pass an examination, go through a course of study, etc.: I was
able to get all my students through, except three whose English
was the weakest. 2. put smb. in touch with a person by telephone:
After some time the operator finally got me through.
get tied up • get tied up in knots
get tied up —(coll.) 
1
. become deeply involved with smb.:
Mazie had just managed to get out of a terrible marriage and
she didn’t want to get tied up with anyone. 2. be held up or
kept busy with people or things: I meant to come round yes-
terday evening, but I got tied up with people.
get tied up in knots —(coll.) become very anxious or worried:
Don’t get tied up in knots over grammar. It’s not worth it and
it will only put you off writing.
Note: 
The expression does not correlate in meaning with the
phrase get knotted—(UK sl.) used to rudely tell a person to go
away (and stop being annoying ): I don’t know why you didn’t
tell him to get knotted and be done with it.