TORONTO -- Some 5,000 President’s Choice Optimum members are frustrated after a promotional event error clawed back valuable points they thought they had earned in what Shoppers Drug Mart called a "glitch."

On Monday, the program which has roughly 18 million members, offered users a chance to win one million points if they spent at least $60 in the “Load. Shop. Surprise” promotion.

Peterborough resident Melynda Dee was shopping for a few things she needed when she heard about the promotion.

“Why not try for extra points?” she said, speaking to CTV News Toronto. “I knew I had enough to qualify for the offer.”

Multiple customers said they were being awarded with a huge number of points in the hours following their purchases, even if they didn’t win the grand prize.

“I was like ‘wow’, I won 301,000 points!” Dee said.

“I didn’t expect to win anything, but then I went out to the car and I had 340,000 points,” Doug Biers, another customer, said.

But that feeling of excitement quickly turned into one of disappointment as dozens of users began complaining on social media that their points had disappeared. 

“Heartbreaking and extremely disappointing,” tweeted one PC Optimum member. “Not acceptable and very misleading,” said another.

For Biers, the claw-back was especially disappointing as he’s currently on disability.

“I was so excited because its Christmas time and the money’s really handy to make it a little more special for Christmas.”

However, in a statement to CTV News Toronto on Tuesday, PC Optimum’s parent company Loblaw said they’ve since corrected the issue.

“On December 9, a system error resulted in some of our PC Optimum members receiving an incorrect amount of points when shopping at Shoppers Drug Mart,” the statement reads.

“We will be re-instating those points associated with the promotion shortly and hope this helps everyone have a little bit of a happier holiday.”

 With files from Nick Dixon.