Untrained Salesman

Bought a rear crank seal for my Colt, salesman assured me that one one size fit all on my specific engine. After fitting the new seal, one hell of a job, it's leaking more than ever. Took the old seal and new seal to another parts dealer and they told me there are two seals for my specific engine. Paid R2800 labour for the job and now have to pay again for the seal plus the removal and fitmen. Please train your salespersons