I think T-mobile is trying to bamboozle my mom

Recently moved, and was talking to my mom about phone service in the area. Surprisingly T-mobile gives us the best reception being a bit into the country. So I asked her what her typical bill looked like, and she was paying well over $300 bucks for lines of a legacy unlimited plan, a line of a lower level legacy phone plan, and a pair of tablets. Told her to stop by T-mobile store and consult them about upgrading to the current T-Mobile one plan. I wasn't there, but from what I gathered the employee was either really unaware or just trying to keep her on the more expensive plan.

• Told her to ask about T-mobile one. "Oh, you don't want that. It'll be wayyy more than what you pay now"

• Told her to ask about qualifying for the promotional line plan. (2 ONE lines, get one free) "Sorry, we don't do that."

I tried to look at her itemized bill but dear god they're awful. Once I figured it out, it made even less sense because she was paying $90 on devices, and the rest on plan.

Now, I'm not sure if there is some policy I'm missing, like they aren't allowed to change their plan until their 2-year is up? But it was mind boggling to hear how un-helpful and dismissive they were. I'm sure employees on the sales floor make commission, but I don't see how it benefits them in this situation.. like they're just taking advantage of customers who don't know better.

In the meantime I'll try to convince her to get on the website and look at it through there, but she hates the internet as most older people do.

I was considering switching to T-mobile myself, but this really put me on guard and I will have to wait and see how this is resolved, but I really am hoping it was just a lazy kid that didn't feel like helping anybody or some other one-off issue.

TLDR; T-mobile told my mom her $210 legacy plan was cheaper than T-mobile one, and also promotionals don't exist.

Edit: because I realize this seems really complain-y and kind of is, I was more hoping to share my experience, and see if others have had similar issues. Especially if anybody who switched from a legacy plan to a ONE plan who wouldn't mind trying to recall any fees or the price-gap between them. Also once its all settled, probably later today, I fully intend to update it hopefully for the better.