What is the exact difference between "が世話になって and "に世話になって

Question

So this character says to this girl

課長にはいつもお世話になってます。。。 Aka "The section chief (your husband) is always helping me"

But then this girl says to him

いつも主人が世話になってます aka "Thanks for always taking care of my husband/helping my husband"

How does it work?

Answer 1

Aが[/は]Bにお世話になる literally means A receives care from B.

Those sentences can be understood as:

• 私は/が課長にいつもお世話になってます - I always receive care from chief.

• いつも主人があなたにお世話になってます - My husband always receives care from you.

Thank you is just implied.