A man who changed his plea from guilty to not guilty and back again several times in the robbery of an Old Town Alexandria store, in which jewelry valued at about $100,000 was taken, switched to guilty for a final time yesterday and received an 11-year, nine-month prison sentence.

The sentence given Jeffrey A. Robinson, 23, by Alexandria Circuit Judge Donald M. Haddock concluded a case that was delayed several times by Robinson's changes of mind and his successful arguments that got him a succession of court-appointed attorneys.

Randolph J. Myers, an assistant commonwealth's attorney, said Robinson had been scheduled to plead guilty last Thursday, but minutes before he was due to appear in court, "he told the sheriff's deputy, 'If I can't wear civilian clothes, I'll have a jury trial.' " The case was then rescheduled for yesterday.

Prisoners who plead guilty in the Circuit Court generally wear jail uniforms, while those who plead not guilty are permitted to appear in their everyday clothes.

Robinson appeared for a jury trial yesterday wearing a brown plaid shirt and blue gabardine pants. He then asked, through his fifth court-appointed attorney, T. Rawles Jones, for Judge Haddock to remove himself from the case on grounds that he was prejudiced against Robinson.

"Your attitude shows a lack of cooperation," Haddock told Robinson, and promptly began the trial.

The first witness, Gladys Irvin, owner of Today's Cargo jewelry store, identified Robinson as the man who robbed the store of gold necklaces and bracelets and precious gems on Sept. 30, 1983.

Robinson, who lives at 1700 16th St. SE, then switched his plea to guilty for the last time, and Haddock imposed the sentence.

Myers said Robinson is now serving an eight-year sentence in Maryland for robbery. When he completes that sentence and is moved to Virginia, he will be eligible for parole after two years.