A lot of it also depends on your weight and how many miles you're putting on the wheels. You didn't mention the type of wheels you're using as original or replacement. Entry level and even mid range bikes have pretty low quality spokes on the OEM wheels. I've seen lots of folks that are over 200lbs. and ride quite a lot (100+ miles weekly) that go through an OEM wheel (broken spokes, cracked rims at the eyelet, Etc.) in under a year. A competent, experienced wheelbuilder should be able to guide you into a more robust wheel that will handle your needs. If your local shop keeps putting you on the same wheel you're having issues with, nothing will improve. If that's the case, as the others said, you may want to look of a new bike shop.