Paul McLoughlin was attacked in his Wheatley Londis store by raider Jon Shirley, who left him with a bruised face and in need of eight stitches to his head.
Shirley was recently sentenced to six-and-a-half years for armed robbery and possession of an imitation firearm, with the possibility of release halfway through his sentence.
"I'm unhappy about the length of the sentence and so are the police. It should be appealed," said Paul. "The judge was far
too lenient on him. Retailers should be getting protection from the courts."
Following the sentencing, Thames Valley Police said it would consider referring the case to the Attorney General's Office for consideration under the Unduly Lenient Sentencing procedure.
A spokesman said the Attorney General would then decide whether to refer the sentence to the Court of Appeal for review.
In contrast to the reactions of Paul and the police, the judge presiding over the case said he had initially considered the sentence to be too long, but felt that there was an enormous leap in the seriousness of the type of offences Shirley was prepared to commit.
Shirley has also been linked with several other armed robberies that occurred around the same time as the attack on Wheatley Londis. Thames Valley Police say they are no longer looking for anyone in connection with these raids.