It looks as though the settings on the machine were too high for that area, and you have suffered burns. Not to worry, they should heal just fine. Make sure you are putting sunscreen on the area and keep the chest out of the sun. Contact the clinic you had it done at, so they know the outcome of the treatment to make sure they drop the settings next time. The spots that are burnt may have over treatment and not blend in with the rest of the skin. In that case, you'll need another treatment with lower settings to blend it all in. Using a protective cream such as iS Clinical Sheald will speed up the recovery time. Make sure to contact the clinic it was performed at. If another treatment is needed, they may offer it discounted or complimentary, as this is the technician's error.