Kenneth Cumming, 50, had left his scooter parked underneath the window of his home in Firrhill Park when it was stolen.
Police recovered the vehicle nearby, but vandals had caused damage costing £2000.
Mr Cumming, who leased the scooter through Disability Living Allowance, has been told he will not be given a replacement because although he had the key to the scooter in a safe place, he failed to secure the vehicle with a padlock or chain.
He said: “I phoned Motability and they said it was no problem to get me a replacement scooter while this one was being fixed.
“But they then sent me a default notice that said because I didn’t secure it, I would not be getting another one and I have 17 days to appeal.
“My district nurse, doctor, family and friends are all supporting my appeal.
“I didn’t know the scooter had to be secured. Apparently, if I had it chained to a lamppost or something like that it would have been fine. It was written somewhere in the small print.
“The scooter is my lifeline. It gives me freedom and if I don’t get another one, I’m trapped.
“I can walk about the house a bit, but I need my mobility scooter to get outside. I don’t know what I’m going to do if I lose it for good.”
Mr Cumming, who suffers from osteoarthritis, angina, gout, and is severely overweight, lives with his wife Ann, 52, who is also disabled, and their daughter, Christina, 21, who acts as their carer.
He explained that the thieves had put the vehicle into “push” mode, meaning it could be wheeled away from the house. The vandals broke off its wing mirrors and indicators, tore up the seat and smashed one of the lights in the attack earlier this month.
City councillor Angela Blacklock, who has campaigned on disability issues in the past, said: “I would have thought he deserves a second chance. He has obviously made a mistake.
“It wasn’t his fault the scooter was stolen by thoughtless people. He is the victim.”
A spokesman for Motability said customers who lease a scooter through Disability Living Allowance, or the War Pensioners’ Mobility Supplement, benefit from an inclusive package of benefits, including Royal & Sun Alliance insurance, servicing and maintenance.
He said: “There are terms and conditions attached to the Powered Wheelchair and Scooter Scheme insurance policy, which include the requirement that scooters should not be left unattended, unless they are locked and secured to an immoveable object by an appropriate padlock and chain.
“Customers in breach of the terms and conditions may no longer be insured. Customers have the right to appeal and Mr Cumming has been made aware that he has until November 28, 2011 to initiate proceedings.”