This is a sign of extreme stress.
What size tank do you have? Raphael catfish need at least 30Gallons and should be kept in small groups (3+).
If you have anything under 20G I suggest you take it back. If you have anything under 5 Gallons I suggest you re-think the fishkeeping hobby alltogether if you have not done any research or prepared for new inhabitants.
Remember, a fish is an animal, buy buying it you take on its welfare, if you cant care for it properly then you shouldnt be buying it at all.
Ben