Thank you for the query.
You said you have pain but havenot specified the area where you have pain as well as the type of pain . If the pain is present in the teeth on which veneers have been placed then it could be severe sensitivity which presents as pain, for this has to be ruled out by taking an x-ray of all the teeth and if any infection persists in the teeth , then root canal treatment
has to be performed to get rid of the pain and crown should be placed . Root canal ,when done is followed by a course of antibiotic and analgesics.
See your dentist
for further treatment.
Hope this information helps you.