A photographer took some pictures of me and said I could use them to post on instagram and online. They have since said I am not allowed to use 'their work' even though I am the person in the picture. Legally, am I still allowed to use their photos of me even though I don't have their permission?
You cannot use other people's photographs of you without permission. You say they reneged on their permission: have they obtained anything in return for the now reneged permission? For example, your agreement to pose? If they did so, reneging on their promise would void any rights they received in return as well as might make you able to sue for compensation for your time and effort gained under wrong pretenses.
The bad news is that basically all of those reliefs require court intervention. You can send them a cease-and-desist for continuing to use your likeness because they did not hold up their end of the deal, but if they ignore you, you cannot in turn ignore their rights but have to employ a court to make them either stop or reimburse you.
Of course, you'll need to consult an actual lawyer to get a reasonable estimate of the recourses available to you and their respective chances of success should push come to court. That's just my personal opinion.
A few major details need to be known: First, where was the photo taken. I'll assume it was in the United States, but this is the internet, so you could be anywhere. Second, was the photo taken in a public space? In the U.S., you don't need permission to photograph anyone while the person(s) is/are on public property. Reason being is that when you're out in public, you can't assume privacy.
The photographer does not need any signed document from you to use a photo with your likeness for non-commercial purposes. That is to say if the photographer wanted to use the image as fine art and sell the image, you do not have any rights to stop the photographer from doing so. Nor do you have any rights to the money that the photographer makes when selling the print. Yes, the image is of you. However, that doesn't mean anything. The person who pushed the shutter button is the one who owns the copyrights. The only exception that I can think of where it wouldn't be legal to use the image is if you were doing something that was embarrassing. For example, if you were photographed at the moment that your pants fell down and exposed yourself by accident, that would fall under the "true but embarrassing" part of the law as I remember it in my communications law class. I'm not a lawyer, but this is what I remember the law to be in the U.S.
As stated, and assuming that the image was taken on public property, you don't have any legal recourse to the image or for stopping the copyright owner (i.e. the photographer) from using said image anyway they want, just as long as it's not for an advertisement or for any other commercial use.
If the photo was taken on private property, and privacy can be assumed, then you have legal grounds to prevent the use of the image.
The following is for entertainment purposes only. If you have any serious legal concerns, consult a lawyer.
It is difficult to do anything about this type of situation after the fact. As long as the other person is also not using the images, it may not be worth the effort to restore your use of the images.
Unfortunately, you do not have a written record. Next time, get permission in writing, or use your phone to audio record them giving verbal permission. Make sure they state their name, their role, what they are doing, why they are doing it, and what you are allowed to do with the artifacts.
If you cannot get the photographer to sign anything, you can consider doing as Comey did – write a memo to document the event in as much detail as you can. Then share the contents of the memo with several others who can later act as corroborating witnesses. Your witnesses should write their own memos as well to document what, when, and how they were told.
Refuse to allow others to photograph you without a clear agreement in place. Otherwise, find a real photographer who will not bully you with copyright law.
Consider drafting a work for hire agreement that you have photographers sign. This will ensure you retain rights to images you commission and prevent them from misusing your images for their own personal gain.
Consider wearing clothing with unique copyrighted designs to which you have full rights. This will make photographs of you derivative works that cannot be used without your permission. (Clothing generally cannot be copyrighted, but unique designs on clothing can be. See New Media Rights: Can you copyright clothing designs?)
Bodywork may also be used, but you'll need to ensure that the bodywork artist has signed over copyrights to you. Otherwise, you may be involved in a ménage à trois copyright battle with the photographer and bodywork artist.