I originally signed up for a slush pool account because I was trying to receive this contract I had purchased on ebay. This was my first time I needed a mining pool account. Overall I would rate 3 out of 5.
Slush Pool does not sell cloud mining contracts. They are a hash rate aggregating service, so if you don't control physical hash power you cannot use the service. It sounds like you were scammed by somebody impersonating Slush Pool.