Autopay discount NOT given even for checking account

So I moved 6 lines to T-Mobile  Sep 2023 and created business account.
The store manager said there would be $5/line credit for linking checking account.

I did that on the first day of starting the service.

For few months I did not realize they were NOT giving me the $5 credit per line.
I have been calling T-Mobile for 4 months each time a different excuse is given.

1st it was it has to be savings acccount so we switch but it was not that so back to checking account.

Few of them credit the month I called for $30.

Most recent call I escalated to supervisor and she said I am not eligible because we have 6 lines.

So why am I not getting credit for 5 lines?
It seems like they keep coming up with excuses not to pay this credit which is listed on their web site.

Mind you I never had a credit/debit card on the account it’s always been checking/savings account from day1.

We are on Go5G unlimited plan.

What are my options, this seems like deceptive business practice…