anecdotally, i was blacklisted by a certain fortune 100 company because i had turned down a face to face set of interviews in the 4th round the night before. they were really pissed off, for whatever reason, i politely told them that i wasn't interested in the position any longer and that i would have to cancel the interview. i think 15 hour notice is sufficient.
anyway, the reason why i knew i was blacklisted was because i was interviewing for a post with that same company in another region several months (~6) later and as soon as the headhunter put me through to hr, they stopped all communications, no details given.
fwiw you should never burn bridges, but in this case, over time i found that this company was the complete anti-thesis of the type of company that i would want to work for and i thank their hr for donning light on that through their utter ineptitude and incompetence, not because they blacklisted me, but because they were so ridiculously disorganized. the facts: hr could not identify the exact title and position that i was interviewing for correctly, several times i would be interviewing for position x (told by hr, job description in hand), only to figure out that the interviewer was looking for position y and was considering me for position y (which was with the same division, but a different role). when doing a phone interview with the vp of the region, he didn't successfully make it until our 3rd attempt (across 3 differently scheduled days) at a conference call, various reasons which i think were ridiculous: laptop was having problems so he couldn't access the conference call number from his calendar, second time was more forgivable that something important had come up, but i was not given advanced notice, only told after waiting in the conference call for 20 minutes and after 3 emails to hr to figure out why the guy was late.
but to come back to your point, you had gone a bit further than i by accepting an offer, i'm assuming signed a contract, and only weeks later you turned them down. while i agree with some of the posts that that's life, that the company had failed to provide you with a fair valuation/compensation package, but at the same time, i doubt the original company was looking to low-ball you, that's quite possibly what they could pay you given their salary ranges. you did the right thing by not trying to
re-negotiate with the first company, that would be completely disrespectful.
i highly suggest trying to bridge this relationship with the first company, tell them your intent clearly, that you're retracting your acceptance, but be prepared to answer because they will ask why. personally i usually give the truth, but that's up to you. remember, you want to treat people how you expect to be treated.
and overall, let this be a lesson learned, given that i realize the job market is not in the best shape, but i believe that you were a bit eager to take on the first company's offer. a little restraint and negotiation could let you to stretch that offer while not accepting and looking for something else that's more fitting.