Have (one's) foot on (someone's) neck verb phrase
The verb "have" can be replaced by the verb "put".
To have or put one under someone's control or power
Give him what he wants and you'll have your foot on his neck.
It seems you are having your foot on his neck in this deal.
a person who is easily deceived or manipulated to do something, especially giving someone money.
1. To seize or take control of someone, something, or some place with a sudden and fierce attack
2. To gain a rapid and great fame or success in a place, a field or a particular group of people
To be under the control of someone or something
To have someone completely under your control
The verb “have" should be conjugated according to its tense.
The phrase may come from knocking someone down and literally putting your foot on their throat or neck, so they can't get up.
Confusion made worse than before.
There was heavy traffic on the way to work this morning. Confusion worse confounded when some drivers were arguing with each other right in the middle of the street.