A two-man early morning robbery in Cullman didn't go fully like two robbers planned and surveillance video proves it.In the video, two men in ski masks drive up in a Red Hyundai Santa Fe to a Cullman Chevron before 3 a.m.One of the suspects jumps out and walks into the gas station.According to Cullman Police Captain J.P. , the first man through the door in the video proceeds to hold the gas station employee at gunpoint as he takes money from the cash register. The same man pointing the gun at the clerk slapped the employee several times in the head.Investigators told ABC 33/40 the woman is bruised from the assault but recovering at home.But when the robbers tried to drive away with an ATM strapped to their vehicle it completely backfired and severely damaged the car.Captain told ABC 33/40, "No comparison. The amount of money they stole is going to be minimal compared to the amount of damage they did to their vehicle.”Captain says the crooks didn't realize one important fact about the ATM.“They are bolted to the floor. They are bolted onto a concrete pad through the floor,“ says the captain.