Unfortunately, Instagram does not have a support phone number or email address. The best way to get support for Instagram is through its help center, which gives answers and assistance for many common issues. The only other way to contact Instagram is through other social media.
If the issue cannot be resolved, you can contact Instagram through its official Facebook and Twitter pages. These are not support pages, so you are not guaranteed a response, but a response is much more likely if the message is written logically and with a level head. Make sure to be specific and clear about your problem without getting angry, and include a screen shot if possible.