Dr. Hagan has given you some excellent suggestions. It's likely that having one eye with fairly good vision and the other with vision that is "pretty bad" is what's causing your problem with your glasses. By making adjustments to the way the lenses are made (i.e., adjusting the center thickness, vertex distance, base curves), problems with double vision can usually be avoided. Perhaps your eye doctor didn't give any special instructions to the lab about how your lenses should be made. (Experienced eye doctors might be more knowledgeable about this.) You should absolutely not be charged to have your glasses rechecked and the lenses remade. In the future, you might want to see only experienced eye doctors. Wearing contact lenses is another way to avoid the possibility of double vision.
Take the glasses back to where they were made and discuss the problem. If they can't fix it (at no cost to you) then see the "eye doctor" that did the test. Ask for a glasses recheck appointment. Clarify the costs. Most ophthalmologists do not charge to retest the glasses. Fall back position is ask for your money back it the problem persists. You usually have to do this in the first 30 days. Clarify that also
JCH MD