Suspension problem
2000 Volvo S40 Automatic

I have a 2000 volvo s40 and I’ve been having quite a few problems with it. The most recent problem is this thumping noise underneath the driver’s wheel, which increasingly gets worse every time I accelerate. I’ve already took it to a Volvo dealership and they said it was the bushing, so I naturally let them fix it. Well no sooner did I drive it off the lot and it was still making the same sound. So I took it back and told them that it is making the same noise and they said they didn’t have time to look at it, that day. So I took it to another dealer who said it was the bearing, so I let him fix it. And no sooner did I drive it off the lot the problem was still there. I have been charged a total of 500 dollars for this problem that hasn’t been fixed. I’m asking as kindly as possible What do you think it could be? And if you tell me its a ball joint issue, I'm going to be one hot red head.