Carol Forde, of Levaghery Gardens, said the court may as well have given the defendant, Tandragee man Derek Rowney, a "pat on the back".
Rowney received a three-year suspended sentence after pleading guilty to possessing and supplying the class A drug. An initial charge of manslaughter was not proceeded with.
Carol's son Jamie Forde (21) died on December 20, 2008 after taking what his mother was told was a "massive dose" of ecstasy.
The Portadown father-of-two had been earning some extra money by helping Mr Rowney do a painting job in Newry when he became ill after taking the drug. He died later in Daisy Hill Hospital.
punishment
Speaking this week from the Killicomaine home of her sister, Mrs Mandy Templeton, Mrs Forde said, "I know nothing is ever going to bring Jamie back but I could have accepted it more if he (Rowney) had got some sort of prison sentence. Even three months would have been something.
"You keep hearing about a crackdown on drugs but when offenders get to court, they say they're sorry and that's it. There's no punishment. I feel the justice system has let us down. We have got no justice for Jamie."
The past year has been an ordeal for Mrs Forde, her husband David, son Christopher (19) and the extended family.
They had to wait a year before they could finally lay Jamie to rest as it was only last month that his heart, brain and jaw were released back to the family, after being kept for a detailed post-mortem.
"My GP explained the post-mortem results to me," said Mrs Forde. "It seems that Jamie had taken a huge dose of ecstasy."
There are many aspects of Jamie's death that the family is struggling to understand, not least of all why he took the drug in the first place, and other matters which the family feels weren't brought to light during the court case.
"The kids weren't even mentioned in court, yet there are two kids left without a dad," said Mrs Forde.
While Mrs Forde admits that Jamie had dabbled with drugs in the past, she is adamant that he hadn't been taking anything since a close brush with death five years ago.
She explained, "When Jamie was 16 someone gave him drugs and he took them. His arm went through a window and he cut it badly. On his way to the hospital his heart stopped and he very nearly died.
"Since that day, he would always have warned anyone against taking drugs. He enjoyed a beer but that was it. There was one thing about Jamie and that was that he couldn't lie to me."
marry
Jamie, who had two children with his partner Carol Gates - Chloe, now aged four, and Jack, 2, - had gone to Newry to help Mr Rowney paint an hotel room. Said his mum, "He had asked Carol to marry him and he wanted to earn some extra money to celebrate their engagement.
"They had gone down to Newry on the Friday night. The last time I saw him he was smiling as he got into the van and I said 'I'll see you later, son'. The next time I saw him he was lying dead in hospital. He just looked like he was sleeping.
"Apparently, the medical staff had worked on him for half an hour in the hotel room and half an hour in the hospital, but they couldn't save him."
She added, "Jamie didn't have a bad bone in his body. He would have gone out of his way to help anybody, and he really loved his kids.
"We have got our sentence. Jamie is dead and gone and the kids are left without a father, but he (Rowney) walked free.
"Jamie was so good-hearted. I know he is dead but in my heart I feel he is still here."
His dad David agreed, "Every time the door opens I still think he's going to come in."
Jamie's girlfriend Carol Gates said her partner of five years had been looking forward to teaching the children to play football."
Jamie's aunt, Mrs Mandy Templeton, was also very close to her nephew, as were her children Stephen (23) and Leanne (22). She said, "Stephen tries to keep an eye out for the kids now, as their dad isn't around to do it.
"As a family, we would say to any young person - don't go near drugs. You don't know what you are taking."