Where are you? Some local shops/labs are very poor and APUGers can give you sources of processing and printing but there's no point unless we know where you are.

I take it that these are B&W prints from B&W negs but are the prints silver gelatin, RA4 balanced for B&W prints or inkjets?

If you are in the U.K. try Ilford's service. Proper processing and silver gelatin paper. If the prints from Ilford are poor then you can conclude that it was your exposure. I have seen Ilford's care and professionalism and it is second to none