Most bike shops do not fix tubes, they replace them in my experience. Sounds to me like they replaced the tube with a Slime tube. More expensive and probably more profitable to the shop. Either they did not remove the cause of the original flat from the tire or you got a new puncture while riding home.
I agree, learn to change tubes or fix flats yourself. A real money saver and you will not be stuck while out riding when you have another flat tire.
__________________
Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
Visit and join the Yahoo Geared Hub Bikes group for support and links.
http://groups.yahoo.com/group/Geared_hub_bikes/