BMW steering

I was driving fine when my 330IC would not turn easily. I was near where I bought it so I drove it right over. They stated the rack had went out and was leaking. Later they called and said the steering pump had gone out and while I was replacing that I should replace the reserve you put the fluids in. I got my car back two weeks later and the car was fine at high speeds however at low speeds it was hard to turn. Although the car seemed tighter on turns at low speeds was difficult to turn. I called the repair shop immediately and told them my findings and wanted to drive another car like mine because if my rack had gone out and pump I had a problem that was getting worse and I didn't know how it should drive when it was not broken. I bought this car used and unfortunately less than 6000 miles later this happens. Can you give me any advice and tell me what adjustments they may have missed to be so hard to turn at low speeds. This is my dream car and was in immaculate shape: no dings, low mileage, only 52,000 and well in what one would consider mint. Then this happens. Please tell me what you think.
Sincerely,
DonPen828