V Beam Laser vs Pulsed Dye Laser, differences?

A pulse dye laser (PDL) is a Vbeam laser. They primarily target "red" areas of the face such as erythema of rosacea, small blood vessels, etc. Depending on the settings and your skin type/color it is possible to have purpura after treatment is completed. Scarring is always a possibility after any laser used on the face especially in the non-Caucasian population. It is always important to seek a board certified dermatologist when obtaining lasers as dermatologists have extensive laser training during residency and are trained to deal with potential complications from laser surgery. 

The Vbeam is a pulsed dye laser. I am sorry to hear of your bad experience but it is really impossible to say. All lasers have serious side effects when not used properly - whether the incorrect laser is used for your skin type, the settings are wrong, the laser is done on freshly tanned skin - there are many factors at play so while I cannot say what happened, I can say that it is critical that you do not have laser performed by anyone who is not a medical professional with extensive experience.