i bought a businees and we signed a no compete agreement , now the old owner is competing .what can i do

i bought an office supply store and computer repair business , the old owner suggested a no compete agreement, so we did . I am getting checks in the mail from from businesses in the area for him, i also have had several customers inform me they have seen him working on computers at other places, i make monthly payments to the old owner for the businesses and i rent the building from him. in my opinion he is taking me to the cleaners.