can this ruin my credit?

[gottadance]

Back in April I was suppose to get initiated but the day before i decided that i didn't want to and I wanted to wait and make sure i wasn't transferring
I told my pledge mom told me thats fine and she'll call me later (which she never did)
June comes and i have intiation fees on my online bill I e-mail and called our finacial person but she never responded after calling her like 10 times in 2 weeks i finally got a hold of her and she told me to ignore it
My bill now says its severely passed due that that as part of the blah blah fair act they are attempting to collect a debt from me
on top of intiation theres also jewelry billings (for this upcoming fall rush) and house dues for intitated members this is coming up to 350 dollars

my mom says now i have a debt on my record and this is going to ruin my credit. is that true?
I was telling one of my sisters this story (how they won't return my calls and stuff) and she told me its because they think i want to pledge another sorority when i transfer so if I have this bill over there the new sorority will not give me a bid)
What i'm worried about is ruining my credit lol maybe i'm just being stupid but i don't know anything about this and I'm going on what others have told me (mostly mom haha)