Good advice there, Joe, it certainly does appear that the chainsaw shop is lacking in both expertise and of good workshop practice. Fitting a brand new chain on a badly worn drive sprocket can be very dangerous for the operator.
I,too, believe Brian has been conned by them,they should have supplied him with a new sprocket.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl