Ignition Coils Failure problems of the 1996 Chevrolet Beretta

After a length discussion with service manager, bryan radin, today I was told the work was not under warranty due to the space in the repair dates and I would be charge the full rates. Only after I pointed out that my ignition coils have been previously replaced and have a life time warranty a deduction in the bill was made. I have been given excuse upon excuse of what the problem could be but I still find myself towing my car back to the dealership weeks later with the same recurring problems.