It depends on the amount of competition and how qualified your listing is relative to the keywords that your business has been optimized for.
A listing could see an immediate ranking change depending on a number of factors, up to and including cache changes or updates done by other sites in the area. Sites compete with each other in a number of ways - some good and some bad. The ideal way would be through relevant content pages - not just spammy links crammed together. A professional SEO company will make it their priority to keep everything legal and follow Google's guidelines closely so as not only to gain rankings but also maintain them over time because Google can apply penalties if you violate those standards.
The answer to this is fairly complicated, but the short answer is no. The reasoning for this, in a nutshell, is that .com domains are not exclusively better or worse for SEO. it's more about maximizing your domain name by getting as many backlinks as possible (provided those backlinks come from relevant sites). In addition to that, you should check Google News Crawl aka how often Google visits your site to see if it comes up in response to related searches - since if it doesn't appear reliably then people will be less likely to find and follow the links on your site. So while there's no one hard-fast rule about which domain extension is better - there might be specialized cases where one would work better than