<human>: Can you succinctly summarize the text in 1-3 sentences?

Basically, Me and my brother and his GF are employed and still live with our parents (better than renting and we save up for our own homes, not really taboo where I am) Mom talked with us about building a small extension to the front of the house just to have more room, my bro and I agreed to pitch in 1/3 each along with her, so 3 x $25000 TT (around $11,800 USD total, Dad said he was comfy and didn't really want to get involved but that's besides the point)

Anyway, mom finds this guy she found working on another home and made arrangements with him to start, From 3 weeks ago to now, they've so far cleared the building site and put down the foundation pillars, now like I said before, me and my bro work so we sorta left things in mom's hands but what's got me concerned now that i've been caught up on what's been happening, is she's basically been giving him money every week and the work has barely started, not only that, she hasn't been receiving any receipts for the transactions or bills for materials, no technical drawing of the work, he's just going based on mom's description he got the first time, it's like she's throwing money at the guy  and saying' uh yeah, here,just get shit done' and goes about her day

My dad decided to finally get involved after seeing these red flags and observing the guys behavior, fast talker, over friendly, only really here when he needs money and kinds of materials they're using, old looking tools, beat up wood,
we're basically wondering where the money spent so far went into

I know this is probably all our faults for not being very attentive, in fact my mom does have a history of dealing with scammy tradesmen for other things, but we're making a move now cuz this just seems so unprofessional, next time he comes, we're going to sit and discuss with him the work and financials, is there anyone who's had this situation before? Did things turn sour or worse? Did you cut your losses?
also would like to know if there are any specific questions to ask as I know next to nothing about contractor work  :/
<bot>: Mom has a history of dealing with scammy tradesmen, seems like she may have picked up another one who's building extension onto the house, may need advice on how to proceed?