I think it is unfortunate that the meat shop did not agree to grind it up further. Butchers typically make sausages and other processed meats including haggis and should have the ability to grind it up more. In my experience you just run it through the grinder again. Poor customer service.
By a meat block perhaps your friend means a Meat Mallet? That might work considering the meat is already ground a certain amount. How about mashing with a rolling pin or potato masher?
Other wise a traditional meat grinder or small food chopper would do the job and are not very expensive.
