HiCustomer this will probably be a straightforward repair but will require access to a code scanner. Any reputable, up-to-date repair facility will have a code scanner. The scanner accesses the car's on board computers and looks for fault codes. Since your ABS light has been coming on, most likely there is a fault code stored. The code will point the technician in the right direction to start diagnosis. Find a better repair facility and they should be able to assist you.
As for a recall, there is none that are applicable to your car.
It's unusual to have the light on but no code stored. If your first mechanic does not want to go into diagnosis, then it's really up to you as to finding another mechanic or going to the dealer. A Buick dealer will certainly have the most up to date information and will be more familiar with this car. Many times, a dealer ends up being the cheaper alternative because they can get it repaired right in the least amount of time