1998 Chevy Blazer Rumble and vibration on front rt wheel

I just had the wheel hub assembly replaced on my 98 chev blazer 4wd. It was making a rumbling sound and vibrating when i would hit a bump, make a rt turn, or had to stop abruptly, but would work itself out after a short distance. This was done 2 days ago, and ran fine with no noise or vibrating for about a day. Now it is rumbling even worse and won't stop unless I come to a complete stop, then whithin a few seconds of driving again starts vibrating and rumbling worse than before. Any insight would be helpful as I feel I may be being taken for a ride with this mechanic. Thanks in advance, S. Price